yes I can remove everything.
I'm thinking that you simply attached the lens with the mirror up which will lock up everything, as the lens should only be removable with the mirror down and shutter cocked. If one is not right it will lock everything up.
If you remove the lens can you then move the cocking lever on the body that lowers the mirror? If that works now look at the lens, can you see through it? If so that's good that means the shutter is cocked and you should be able to reattach the lens and be good to go. If you can't see through the lens you need to cock the shutter by rotating the two pins on the rear of the lens counterclockwise until they line up with the green dots, the shutter is now cocked. With the shutter and body both cocked you should be able to reattach the lens and be good to go. Note: If you want to fire the body with an empty film back attached you will need to have the dark slide out and the the multi exposure switch set to multiple, with the back removed nothing special is required just wind and fire.
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