Hammerli Main Spring, How to Change

I'm getting a lot of misfires on my Hammerli International. As per a few people's recommendation it's quite possibly the mainspring just needs to be replaced. Can anyone guide me on replacing it? I can't immediately see how to remove the mainspring as the pin/post that's in the middle of the spring is stiff and won't budge. I'm assuming I need to release the tension on this pin/post while the hammer is not cocked? Any help would be appreciated.

The stamped piece that the bottom of the mainspring is pushing on simply lifts up and out of a slot in the frame. Grab it by the bottom and push up

jglenn21 wrote:The stamped piece that the bottom of the mainspring is pushing on simply lifts up and out of a slot in the frame. Grab it by the bottom and push up

Replaced. Thanks!

The replacement spring has two more coils than the original. When assembled after replacement, the slide feels tighter coming back to the front. Could this have any effect on accuracy?

Only function  maybe

As a side note the exesse shares the same mainspring and FP spring as the 208/215

Try replacing the firing pin also, they may look good but if you are still getting light strikes check that as well it is a easy fix.