Tony Hayes wrote in
:

I could - by using a stepladder - probably reach such screws near the
top, even if on the other side of the panel, but I can't think what to
do about fixings lower down.

Any suggestions - apart from turning ther panels around - most welcome
;-)

Tony

Use standard fence retainers (can't think of a proper name for them).
Two each side, one near the top, one near the bottom. Each of these
attach to the posts by a single screw. So, having the retainers already
screwed to the posts, offer up the fence panel at a slight angle to the
top two, slide it upwards. Push it higher than you need it to be,
straighten it and drop it through the lower retainers. Then, using
something or other to hold the panel at the right height, put stainless
steel screws through the hole(s) in the side of the retainers. Job done.
Simply reverse to remove.

The retainers are just U-shaped metal a couple of inches long. Available
from any halfway decent fence supplier.

Rod

PS Panel clips seems to be one name. See
http://www.diydata.com/projects/woodenfence/fencepanel.htm for one
example.