Ha Ha very droll!!!! Seriously, I have 2 boxes, 1 an AMSTRAD, the other a GRUNDIG. I'm having issues with both and have located the new installation menu on the GRUNDIG, but not the AMSTRAD.
It says this on google. Don't know if it's any help:
How do I access the Service Menu?.
To access the Service Menu you have to press a certain sequence of keys:
'Services'
'4'
'0', '1', 'Select'
This brings up the Service Menu, with various options, including new installation, setting the RF out channel, LNB options, and the 'magic eye' power select.
It's exactly the same for ALL Sky boxes, "normal" boxes or Sky+. If it doesn't work on your Amstrad Sky+ box then either you are doing it wrong, using the wrong remote (Sky+ box MUST use Sky+ {silver} remote, not Sky {blue} remote), or the box needs attention.