Open the back ramp door to a square postion, figure where you want to put your eye bolts, make them heavy enough to support the expected weight you'll have on the back ramp door. (Mine are 1/2" eye bolts).
Then figure the 45* angle from the end of the ramp door to approximtely 6" down from the top corners of the frame opening and the end of the ramp door, this will be the cable or chain length you will need.
Get a couple of turn buckles that will support the weight expected, have about 4-6" of total adjustment, cut 1 foot off top or bottom your choice of the 45* angle cables/chains and install the double eyed turn buckle to one end of the short and long pieces securely.
This will leave about 1' of excess chain, past the turn buckle then figure where to install the 1/2" eye bolts on the ramp door edge, CHECK to MAKE SURE that the eye bolts will NOT interfere with the closing of the ramp door when your are not using these cables/chains etc.
Open the eyes on both ends of the ramp door AND ramp frame enough to just be able to freely insert a link of chain onto the eyebolt on each side.
To use, put a end chain link into the to ramp frame eye bolt and then figure out which chain link will hold the ramp in the level postion and insert that chain link onto the bottom eyebolt, then use the turn buckle to get everything level etc.
Waterproof around all eyebolts etc.
You can use shorter chain sections if you do some carefull measuring on the 45* angle etc. Do some carfull eyeballing BEFORE you get drill happy and start punching holes, check the CONSTRUCTION of your ramp door and frame, you may be able to use a couple of flat 1/8" or 3/16" plates with a 5/8" hole and bolt to the frame opening and still have the ramp door to close with NO hangups etc, instead of drilling etc. :B
Tia,
Don
