Need help with door weatherstripping

[carguy46]

I have a '69 Barracuda Fastback. Bought new weatherstripping for door windows. There is a channel attached to both windows (drivers side and passenger side). Directions say remove old one, did that. Slide in new! Yea right! The channel has 3 little bumps (to hold in weatherstripping). But can't get new stripping past them. May also be known as windlace.

 

[carguy46]

Thanks for the views,took it to a glass shop, $25 (cash) to install.