1. Calculated desired length of ramp to 6′ then divided length by 3.5″ for number of pieces required to run down the ramp horizontally.
2.  Bought 15 2″x4″x 8′ treated wood which meant I could have 3 pieces running lengthwise
3. Cut 12 pieces in half to fit the desired overall length of ramp + top and bottom piece
4. Cut 3 pieces to 6′ and angled from shed to ground
5. Secure the frame with the shed using 4″ lag screws  into the 4×4 of shed framing
6. Placed 2″‘x4″x4’ on the frame and secured with 3″ decking screws.
7. Ramp finished to include two coatings of non- skid paint.

Job finished in just over two hrs.  Now I can drive lawn tractor out without setting up removable ramps!