Tips removing pile weather stripping from window side

Hello. I will be replacing the pile weather stripping on windows. I'm confident I have the right pile (58-127) for my Nuair single hung windows . It's fairly simple to remove the old pile from the sash side, but I'm not sure how to do it for the pile that's installed on the window frame side. There doesn't seem to be much space to slide it out the same way your would for the sash, and I'm hesitant to cut it out if I'm unable to get the new pile in. Thankfully, the pile on the window frame side isn't as worn as the pile on the sash, but if you have any advice on how to remove and replace it, I'd appreciate the help. Thanks.