You absolutely DO NOT have to remove the mainspring to get the recoil lever pin back in. You would be asking for more problems with zero gain to your immediate problem. What you want to do is relieve the pressure exerted on the recoil lever by the mainspring that is preventing you from lining up the holes to put the recoil lever pin back in. Just disconnect the mainsprings hook from the recoil lever bottom bar ... then the recoil lever just slides around in the frame and can easily be lined up to the frame's hole. It really is that simple and I wish I was there to show you. No 'special' tools are needed for the job other than your basic pin punch set and good manual dexterity.
The first time you play with your recoil lever is the most traumatic but after you've done it once or twice it's childs play and can be done in under 4 minutes after that.
The following is a YouTube video that starts with the mainspring out ... this was done to show folks how to re-assemble a Luger mainspring and recoil lever. The part regarding the recoil lever shows how easy it is. But you do not have to remove the mainspring at all but if you do please protect your eyes at a minimum.
https://www.youtube.com/watch?v=J3x5Ie50Bdw