diff --git a/docs/easy-testing.md b/docs/easy-testing.md
new file mode 100644
index 000000000..4f754e66c
--- /dev/null
+++ b/docs/easy-testing.md
@@ -0,0 +1,120 @@
+# Testing changes with AnkiDroid on an X86_64 sim (Linux)
+
+## Setup
+
+Make sure you can build AnkiDroid first.
+
+Install NDK:
+
+- Download https://developer.android.com/studio#command-tools
+- Rename cmdline-tools to $ANDROID_SDK_ROOT/cmdline-tools/latest
+- Get ndk version from rslib/build.grade
+- .github/scripts/install_ndk.sh 22.0.7026061
+
+Install Rust:
+
+- rustup install 1.54.0
+- rustup target add x86_64-linux-android
+- sudo ln -sf /usr/bin/gcc /usr/bin/x86_64--unknown-linux-gnu-gcc
+
+Install protobuf:
+
+- Install protobuf with your package manager
+- pip install protobuf, or see the venv section below
+
+## Limit build to x86_64
+
+So you don't need to install cross compilers, patch the sources to
+only build the x86_64 image for the aar file and jar:
+
+```diff
+diff --git a/rsdroid/build.gradle b/rsdroid/build.gradle
+index bc3a401..7c69a5b 100644
+--- a/rsdroid/build.gradle
++++ b/rsdroid/build.gradle
+@@ -72,7 +72,7 @@ dependencies {
+
+ }
+
+-preBuild.dependsOn "cargoBuild"
++preBuild.dependsOn "cargoBuildX86_64"
+
+ signing {
+     def hasPrivate = project.hasProperty('SIGNING_PRIVATE_KEY')
+diff --git a/rsdroid-testing/build.gradle b/rsdroid-testing/build.gradle
+index 8641b8f..694212e 100644
+--- a/rsdroid-testing/build.gradle
++++ b/rsdroid-testing/build.gradle
+@@ -181,8 +181,6 @@ task copyWindowsOutput(type: Copy) {
+ // TODO: check for cargo
+ // check for targets: x86_64-apple-darwin, x86_64-pc-windows-gnu, TODO: Linux
+
+-processResources.dependsOn preBuildWindows
+-processResources.dependsOn copyWindowsOutput
+ // To fix: "toolchain 'nightly-x86_64-unknown-linux-gnu' is not installed"
+ // execute in bash: rustup toolchain install nightly-x86_64-unknown-linux-gnu
+ // "linker `x86_64-unknown-linux-gnu-gcc` not found"
+```
+
+## Using a custom python venv
+
+If you don't want to `pip install protobuf` globally, you can
+switch to a venv:
+
+```diff
+diff --git a/tools/protoc-gen/protoc-gen.sh b/tools/protoc-gen/protoc-gen.sh
+index d4039ec..3ac5d29 100755
+--- a/tools/protoc-gen/protoc-gen.sh
++++ b/tools/protoc-gen/protoc-gen.sh
+@@ -1,2 +1,3 @@
+ #!/bin/bash
+-./tools/protoc-gen/protoc-gen.py
++
++$HOME/Local/python/misc/bin/python3 ./tools/protoc-gen/protoc-gen.py
+```
+
+## Build
+
+Two files need to be built:
+
+- A .aar file for emulator/device testing
+- A .jar for running unit tests
+
+```
+export ANDROID_SDK_ROOT=$HOME/Android/Sdk
+export PATH=$HOME/Android/Sdk/cmdline-tools/latest/bin/:$PATH
+./gradlew assembleRelease
+NO_CROSS=true ./gradlew rsdroid-testing:build
+```
+
+If your environment is set up to override the default
+Rust output location, you must also set unset CARGO_TARGET_DIR.
+
+## Modify AnkiDroid to use built library
+
+Tell gradle to load the compiled .aar and .jar files from disk:
+
+```diff
+diff --git a/AnkiDroid/build.gradle b/AnkiDroid/build.gradle
+index 2a2d94034..b21c7caff 100644
+--- a/AnkiDroid/build.gradle
++++ b/AnkiDroid/build.gradle
+@@ -271,10 +271,10 @@ dependencies {
+     // - switch the commented and uncommented lines below
+     // - run a gradle sync
+
+-    implementation "io.github.david-allison-1:anki-android-backend:$ankidroid_backend_version"
+-    testImplementation "io.github.david-allison-1:anki-android-backend-testing:$ankidroid_backend_version"
+-    // implementation files("../../Anki-Android-Backend/rsdroid/build/outputs/aar/rsdroid-release.aar")
+-    // testImplementation files("../../Anki-Android-Backend/rsdroid-testing/build/libs/rsdroid-testing-0.1.10.jar")
++    // implementation "io.github.david-allison-1:anki-android-backend:$ankidroid_backend_version"
++    // testImplementation "io.github.david-allison-1:anki-android-backend-testing:$ankidroid_backend_version"
++    implementation files("../../Anki-Android-Backend/rsdroid/build/outputs/aar/rsdroid-release.aar")
++    testImplementation files("../../Anki-Android-Backend/rsdroid-testing/build/libs/rsdroid-testing-0.1.10.jar")
+
+     // On Windows, you can use something like
+     // implementation files("C:\\GitHub\\Rust-Test\\rsdroid\\build\\outputs\\aar\\rsdroid-release.aar")
+```
+
+After making the change, force a gradle sync, and then you should be able to build
+and run the project on an x86_64 emulator/device, and run unit tests.