Bob Its been a long time since I put any up however
It is a lot easier to use the stepped method, if you slope it you will either have to cut the sheets to match the slope , a lot of work, or angle the posts , down right rediculous.
Set out your string line set your first post to the desired depth to suit the panels use a top and a bottom rail to get the distance to the next post get it in place and screw the top and bottom rails in place make sure the post and rails are square and correct using a spirit level and the rails are at the correct distance apart then work your way along, when all the posts and rails are in allow the concrete , I assume you are concreteing in the posts, to set for a day or two then remove the top rails one at a time and slide the sheets in place an re connect the top rail .
Don't put the sheets in while the concrete is setting any wind and you are in trouble have seen people use angle braces 90 deg to the fence at the mid point or a couple of spots to assist in keeping the fence correct while the concrete dries its up to you
Your fence wont be the exact length and the last section you will have to make shorter this is ok as you can overlap the sheets, you may however have to cut a strip of the end of one sheet so take some tin snips and a hachsaw to shorten the last rails, or an angle grinder with a cutting blade
I'd start at the high point and work down the slope its easier to get the steps right and the posts to the right depth
The bottom rails are the ones with drainage holes so keep them a couple of inches clear of the ground this also makes using a wipper snipper easier when cutting the grass
Thats about all I remember mate as I said it's been a while![]()
Oh and buy that cordless impact driver you need for the job , never miss a tool buying chance![]()