RV Repair: Slide out repair, fork lift, different designs

Question
the dirty of it, the header above a 10 year old slide out is rotted.  Seems like a fairly easy thing to replace, simply a header, but getting to it seems tricky.  Remove the lip around the slide from the inside?  Extend the slide further out?  Stops on the slide gears i'm sure.  How to take them off.

Is it worse than simply replacing the header and resealing and then putting back together?

Thanks, Jeff

Answer
Hi Jeff
There are a lot of different designs of slides ,so I'm not really sure on yours.
Here at the shop a job like that would require us to remove the slide   from the rig with a fork lift, so we could easily access the top and sides. But you might be able to do it all from inside, I can't say without seeing it. Once the interior trim is removed, you can see a lot more of the work area, thats where we start.
The gear drive does have stops on it and are easy to figure out and remove. We even slid a small one out and put it on saw horses to work on.

Thom