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Adding a slide awning, or any big awning for that matter, is a multi-person job.
Particularly difficult if you don't have access to reference material, detailing the wall construction of the coach, you don't want to be drilling holes in the side of you coach , only to find there's nothing behind the fiberglass to hold the mounting screws.
JMHO: Phone around for a quote on the awning installed, you'll probably find, a price to your liking; it's been 10 years since I had one installed, but at the time the install price was so reasonable, I felt it wasn't worth my time to try it myself.
99DSDP 3884, Freightliner, XC, CAT 3126B, 300 HP /ALLISON 3060
2000 Caravan toad, Remco & Blue Ox.