Securing third-party stereo

[robf]

Hi,

I have purchased a third-party stereo from Ebay and installed it.

It all went well until it came to the instructions that showed how to secure it (so it doesn't slide out).

Basically, the "pigeon-English" instructions with the stereo want me to bolt a bar to the back of the open slot (fine, that's easy) and then bolt it to the back of the stereo (not fine).

But how can I do that? The slot is only big enough for the stereo so I can't get my hand/spanner in there as well.

Is there a way of perhaps removing the fascia panel around the radio slot so I have more room to bolt this in place (as the stereo fits perfectly but does look like it could slide out very easily)?

If it's not possible to do that would any of the fascia adaptors that are sold (e.g. this one http://www.amazon.co.uk/CITROEN-BERLINGO...B003JIG2HA ) secure the unit in place so it doesn't slide out?

Thanks for any help anyone can provide, much appreciated in advance.

Rob