Originally Posted by TitanMike
I had a similar problem with my slide topper. The spline worked out because there was no screw installed at each end. Just a simile sheet metal screw installed in the channel to keep the spline from working out as the wind blows over the awning material.
I didn't try to push the spline back in but rather attacked the problem from the other end. I pushed some new spline material int the opposite end where the hem of the awninhg/topper material was hemmed and secured both ends with a self drill/tap sheet metal screw.
Has been fine for the last couple years and a LOT of miles.
I was going to suggest looking at the opposite side and seeing if you could push it in from that end after you cut the excess off. Then fill both ends with silicone sealant. I squirted that stuff into my awnings and they haven't worked their way out again.
One person said they extended the slide, grabbed the tube with a tool, maybe channel locks?, and rotated the tube slightly to take the pressure off. They were able to push it back in then.