When mine broke, I bought a couple of them from Chambers. You need to remove the trigger and trigger lever before you can remove the sear. Very simple, see my video. Getting the new spring on without bending (spreading too far) it is what you have to be careful of. Try putting the old one back on/off/on a few times to get the hang of it.https://www.gunspares.co.uk/products/24955/TO6-Trigger-Unit/