I just changed mine on my P5C to 8# wolfs. You have to mildly compress the spring from the rear of the slide, turn the spring 90 degrees and pull it out through the side hole on the slide. You would think it pulls out from the front but it must pull from the back. You put the new ones in the same way from the back forward. Make sure to set the retainers in and feed the spring over them because you can't get the retainers in from the front once the springs are in. The spring and retainer are a tight fit and if you rotate the spring as you feed it it has a better chance of "screwing" on to the retainer. Hope this helps, good luck.