How do I get the back seat to flip forward/down once the seat pull tab has mistakenly been folded in & under the seat (Subaru Outback 2003)?

SOURCE: Volvo V70 rear seatbelt jammed

i know this sounds rough, but pull the seat belt with both hands as hard as you can, this will more than likely free the seat belt, some of the seat belt may have jammed in the gear inside the roller box.......

SOURCE: Volvo V70 rear seatbelt jammed

you can remove the bolt that holds the seatbelt to the floor by pulling off the seatpad where the belt goes to the floor and then raise the seat and the belt should reset. this happens on my passenger side rear seat.

SOURCE: drivers power seat will not move forward or back.

check first to make sure there is nothing caught in the track or under the seat or there maybe a bad wire on the power motor itself and yes there should be a fuse or relay check under the dash for the box there and the diagram will tell if you if one is there or check the relay box under the hood for the relay for it

SOURCE: My rear seatbelt in my subaru outback is locked and wont pull out to buckle up. Can it be fixed

I assume you've already worked the seat belt end back and forth with force. Did the belt move at all? Did you remove the rear seat bottom cusion from the car? That will give you additional leverage on the belt.
If the belt twisted the last time it was used and then rolled up, you need to go to the dealer or an upholstery shop for help.

SOURCE: 2003 Toyota Corolla LE back seat fold down? how?!

Open the back trunk, look near the top of the trunk, and pull the two black levers. They have a seat folding down symbol. That will release the locks to fold the back seat down.