One of the "tools" in my gun tool box is this piece of wood. See the little screw sticking up out of the wood? Makes it easy to set the main spring "cap" on and then push downwards to line up the holes in the frame and the slot in the cap so the pin can be pushed back in.
I've found the P07/P09 lanyard loop/caps are plastic and will deform when you put enough pressure on them. I try not to do it very often. No issue with the CZ75 types as they are metal/steel.
And, the more you work on it, the more you learn, the better you get at it, the easier it is and the happier you are with the work you do on them.