LayerCake adds a tab to the Compositor's sidebar. Open a Compositing workspace (or any Node Editor set to Compositor), press N to show the sidebar and switch to the LayerCake tab. There are no add-on preferences to configure — every option lives in that panel.

The Combined output matches your render. To rebalance it, expand the Pass Factors panel on the group node and pull a light path or Emission toward 0 — or enter the group to regrade a branch directly. Turn on Expose Extra Passes and click Update This Source to also get AO, Depth, Normal, Vector and the index passes as named outputs.

When the source carries Cryptomatte Object or Material layers, LayerCake places pickers inside the group and exposes their Matte and Pick outputs. Click Pick Object or Pick Material, then click in the backdrop to add IDs — Alt/Opt-click to remove, Enter to finish.

Each Render Layer or EXR is treated independently. Use Bake All Sources to build a separate, editable LayerCake for every source in the tree at once — each keeps its own Viewer and can be updated or removed on its own.