Confederate wrote:Anytime you disturb the factory crimp you run the risk of the bible cap exploding under the right (or wrong, depending on how you look at it) conditions, which could spell disaster.
I would agree 100% if this was something that he was placing back into service as a door lock... but, given that this is something he's just playing around with for picking practice, I think that words like "exploding" and "disaster" might freak the poor guy out.

Confederate is right: with most locks, it's usually preferable to remove the plug and repin the lock that way. (See the repinning advice that I linked to in my earlier post.) If you have slid the spring cover off, though, don't worry... just make sure that it's not been bent when you were removing it: it should fit in securely again when you slide it back in.
If that strip is bent or not properly seated there's a risk that it could pop off later if you push up too hard on the pins... so, in deference to Confederate's point, it would not be a good idea to install that lock back into a door (
e.g., to actually secure something like your house) unless you're sure that strip is properly crimped back into place... but for picking practice, you're likely fine.