I have a Wolf but I think the fire group is pretty much identical to the Optima. If you look into the upside-down receiver fire group cavity with the barrel to your left and the stock to your right, the barrel release lever will be on the side of the cavity close to you. The hammer spring will be on the opposite side of the hammer. In other words, from next to your body to far (we're looking upside-down so far is the left side of the receiver, as you would address the firearm) the following items are stacked on the hammer pin: spacer, hammer, and spring, in that order.
Both legs of the spring will be on the right side (stock side) of the pin. The leg of the spring with the 90 degree bend will be resting on the hammer with the pointy end towards you. The straight leg of the spring will be nestled into the groove in the spring retainer pin that's pressed into the hammer. There is enough tension on the spring to trap the spring in position between these two points, without the pin installed.
To install most of the receiver assemblies (barrel release lever, hammer, trigger assembly) you'll probably need short pins to temporarily hold everything together while you slide an assembly into the receiver. Then drive them out with the insertion of the actual pin.
Let me know if you need any more info. Keep in mind that I'm just a hobby gunsmith--not a pro. And this is how my Wolf works. Don't know about an Optima for sure.
Too bad you've voided your warranty
but, if the rifle functioned before, it should be simple matter to keep it functioning. These are pretty simple firearms. Please let me know how it goes.
