[MENTION=60670]jlynn77[/MENTION]
Check the floor very well, and reinforce it if it’s just stapled in place because the washer may shake it loose. Ours did, and I got to remove and reinstall it just for fun.
Venting will be specific to your trailer, and there should be a sticker marking the spot to drill on the inside. Personally I wouldn’t trust that. I used a small 1/8” drill bit and drilled about every 1/2” vertically and horizontally from the center of where I wanted the hole, to make absolutely certain I wasn’t going to hit an aluminum frame member with the hole saw. Once you know that for sure, it’s easy…drill with the hole saw from the inside until the pilot bit penetrates the outside, then go outside and drill from that direction and meet in the middle so you don’t splinter the outside fiberglass.