Taking the top of the Lafette off from the fire control mechanism is a PAIN. It took me a long time to figure this out. There may very well be a better way, but this is how I had to do it...
These large screws actually don't do much... but I removed them. It seemed like it would be easy to undo the screws and take the little support legs off, but noooo... The screws just are, well, screws. But when you remove them, nothing comes off.
This is a blurry picture, and I apologize... The top/front of the little arms are held in place by a large, flat headed, pin. To get the top of the Lafette free, I had to remove ONE of these pins. They resemble a shoulder bolt but the end is not threaded. Instead, it is hollow. The pins fit through a thick washer and the hollow end is peened out so the pins are locked in place. I had to use a smal punch that would fit inside the hollow pin end, and hammer out the pin from the washer.
When you hammer out one pin, you can actually slide and slip the two legs off of the fire control unit. One leg will now be loose (the one you unpinned) and the other will be attached to the top of the Lafette.
I need to figure out how I will reassemble that pin. I am not keen on having to try to hammer it back into place. I may cheat and use a modern shoulder bolt and nut, painted to match the Lafette. I would keep the original pin and washer. This would make it a lot easier to take the Lafette down again in the future. The use of a flat headed shoulder bolt and nut on the inide would be largely invisible too.
To remove the fire control assembly, simply unscrew the metal firing arc strip (four bolts and nuts). Lift this off the lower Lafette frame, remove the two limiter clips, and slide off the mechanism from the arc. The little spring loaded clips are in two parts, with a spring in the middle.
The optics mount is easy to remove from the top left rear of the upper Lafette. There are some folded over lock washers that need to be carefully flattened out to free the nuts. You will notice these on a few parts of the Lafette. Instead of using a crown type lock washer, the Germans used a thin, flat, Washer, and then folded one edge up and alongside the nut to hold it in place.
There are a lot of parts on the optics mount. A couple do not seem to come apart. I also couldn't get the large wing nut off. Everything was very very dirty
A problem I ran into with my gun and Lafette combination is that the Wise Lite Arms MG42/M53 is about half an inch longer than a "real" MG42. SO, the front locking lug under the barrel does NOT fit into the clamp on the Lafette
I really don't know how to solve this. Well, may be I do... The gun locks in place securely at the back. The gun's lug does fit down into the mount at the front... just the clamp does not lock it in place. So, I think a leather strap around the top of the Lafette and over the barrel jacket may do the trick. I can't see using the gun on the Lafette too much. It's mostly for show. And, when I do use it, it would be on a hard, smooth, even surface. I've shot the gun already and don't see where the recoil would dislocate the gun if secured at the front with a strap. The only other solutions I could think of were having someone unweld and reweld the lug under the gun, or having a new clamp machined for the Lafette (too expensive).