I had a similar situation. I have a steep better than 20% slope that I used to grow Christmas trees on. It had been neglected for many years so it became very veiny with grapes. Virginia creeper, raspberries, and other plants I started by having to clear the Christmas trees out, which was a lot of work Once the ground was somewhat cleared. I made an A-frame out of three pieces of 2 x 4 with a level going across the bottom of the A-frame. I started at one end and worked my way across the slope marking each point so that they would be all on the same elevation. I then used a broad Fork to loosen up the soil. The broad fork also helped to dig out a lot of the Virginia creeper and Christmas tree roots. I did about a five or 6 foot wide path with the broad Fork. I then took a rake and standing on the low side of the hill I use the rake to pull the soil down and made a level area. These rows are only about 4 feet wide. once I had the area leveled out I planted trees. I also planted comfrey in there to try to keep the other weeds out. It’s an ongoing effort. I only started five years ago, so it’s still pretty weedy and it’s a challenge every year to clean them up it’s a lot of work, but it looks pretty good right now. Hope this helps.
