Look, It's real easy,,,,
Take off the top, lay it on the grass, jump up & down -it will pop out. (Thank you Warren!)
If you want a better job:
Take out the bracing & straighten it out, get new peg board from mega-hardware and if you need better insulation use the foam sleeping mats.
After you pop the dent out, beat it with a block of wood and a rubber mallet.
No biggie, they all are dented on the top. Some more than others.
See me in Aberdeen (L,M 1/2), I'll show you my hard top.
Did I say I love my hard top? It's quiet, warm, less leaks & looks nice.
Art