It shouldn't be that tough. We recommend using the square end og the polymer chamber flag that shipped with the rifle and q small hammer to start the pins. Make sure that you're square with the driving surface against the pin, and start the pin slightly, then use the pin/flag to push it the rest of the way to the open detent position. Don't try to knock it all the way through with one pop of the hammer/mallet.
If it's a factory built rifle, it's already been together , apart, together, and apart again...so I know it can be done.
Our rifles are tight. After a couple/few hundred rounds the anodized surfaces will wear into each other enough to loosen the fit just a little bit...so broken in it will still be tighter than a lot of factory new rifles from other manufacturers.