diff --git a/ethereum-consensus/src/capella/block_processing.rs b/ethereum-consensus/src/capella/block_processing.rs
index 744bcc2fe..07cc1be94 100644
--- a/ethereum-consensus/src/capella/block_processing.rs
+++ b/ethereum-consensus/src/capella/block_processing.rs
@@ -1,11 +1,15 @@
 use crate::{
     capella::{
-        compute_timestamp_at_slot, get_current_epoch, get_randao_mix, process_attestation,
-        process_attester_slashing, process_block_header, process_deposit, process_eth1_data,
-        process_proposer_slashing, process_randao, process_sync_aggregate, process_voluntary_exit,
-        BeaconBlock, BeaconBlockBody, BeaconState, ExecutionEngine, ExecutionPayload,
+        compute_domain, compute_signing_root, compute_timestamp_at_slot, get_current_epoch,
+        get_randao_mix, process_attestation, process_attester_slashing, process_block_header,
+        process_deposit, process_eth1_data, process_proposer_slashing, process_randao,
+        process_sync_aggregate, process_voluntary_exit, BeaconBlock, BeaconBlockBody, BeaconState,
+        BlsPublicKey, DomainType::BlsToExecutionChange, ExecutionEngine, ExecutionPayload,
         ExecutionPayloadHeader, NewPayloadRequest, SignedBlsToExecutionChange,
     },
+    crypto::{hash, verify_signature},
+    primitives::{BLS_WITHDRAWAL_PREFIX, ETH1_ADDRESS_WITHDRAWAL_PREFIX},
+    ssz::ByteVector,
     state_transition::{
         invalid_operation_error, Context, InvalidDeposit, InvalidExecutionPayload,
         InvalidOperation, Result,
@@ -25,7 +29,7 @@ pub fn process_bls_to_execution_change<
     const BYTES_PER_LOGS_BLOOM: usize,
     const MAX_EXTRA_DATA_BYTES: usize,
 >(
-    _state: &mut BeaconState<
+    state: &mut BeaconState<
         SLOTS_PER_HISTORICAL_ROOT,
         HISTORICAL_ROOTS_LIMIT,
         ETH1_DATA_VOTES_BOUND,
@@ -37,10 +41,33 @@ pub fn process_bls_to_execution_change<
         BYTES_PER_LOGS_BLOOM,
         MAX_EXTRA_DATA_BYTES,
     >,
-    _signed_address_change: &mut SignedBlsToExecutionChange,
-    _context: &Context,
+    signed_address_change: &mut SignedBlsToExecutionChange,
+    context: &Context,
 ) -> Result<()> {
-    unimplemented!()
+    let address_change = signed_address_change;
+
+    assert!(address_change.message.validator_index < state.validators.len());
+
+    let validator = &mut state.validators[address_change.message.validator_index];
+
+    assert!(validator.withdrawal_credentials.starts_with(&[BLS_WITHDRAWAL_PREFIX]));
+    assert!(
+        validator.withdrawal_credentials[1..]
+            == hash(address_change.message.from_bls_public_key.as_ref())[1..]
+    );
+
+    let domain =
+        compute_domain(BlsToExecutionChange, None, Some(state.genesis_validators_root), context)?;
+    let signing_root = compute_signing_root(address_change, domain)?;
+    let pk: &BlsPublicKey = &address_change.message.from_bls_public_key;
+    assert!(verify_signature(&pk, signing_root.as_ref(), &address_change.signature,).is_ok());
+    let withdrawal_credentials = vec![ETH1_ADDRESS_WITHDRAWAL_PREFIX];
+
+    let withdrawal_credentials_array: [u8; 32] =
+        withdrawal_credentials.try_into().expect("Wrong size");
+    validator.withdrawal_credentials = ByteVector::try_from(withdrawal_credentials_array.as_ref())
+        .expect("Failed to convert array to ByteVector");
+    Ok(())
 }
 
 pub fn process_operations<
@@ -103,7 +130,7 @@ pub fn process_operations<
                 expected: expected_deposit_count,
                 count: body.deposits.len(),
             },
-        )))
+        )));
     }
     body.proposer_slashings
         .iter_mut()
@@ -175,7 +202,7 @@ pub fn process_execution_payload<
                 expected: state.latest_execution_payload_header.block_hash.clone(),
             }
             .into(),
-        ))
+        ));
     }
 
     let current_epoch = get_current_epoch(state, context);
@@ -187,7 +214,7 @@ pub fn process_execution_payload<
                 expected: randao_mix.clone(),
             }
             .into(),
-        ))
+        ));
     }
 
     let timestamp = compute_timestamp_at_slot(state, state.slot, context)?;
@@ -198,7 +225,7 @@ pub fn process_execution_payload<
                 expected: timestamp,
             }
             .into(),
-        ))
+        ));
     }
 
     let new_payload_request = NewPayloadRequest(payload);
diff --git a/ethereum-consensus/src/capella/bls_to_execution_change.rs b/ethereum-consensus/src/capella/bls_to_execution_change.rs
index 10f094ab8..1304ef2b6 100644
--- a/ethereum-consensus/src/capella/bls_to_execution_change.rs
+++ b/ethereum-consensus/src/capella/bls_to_execution_change.rs
@@ -14,6 +14,6 @@ pub struct BlsToExecutionChange {
 #[derive(Default, Debug, Clone, SimpleSerialize, PartialEq, Eq)]
 #[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
 pub struct SignedBlsToExecutionChange {
-    message: BlsToExecutionChange,
-    signature: BlsSignature,
+    pub message: BlsToExecutionChange,
+    pub signature: BlsSignature,
 }