Front Door Trim / Panel Removal

Hi Martin,this seems quite straightforward, my N/S Door Mirror, is bust internally, been like it for months, just sourced a complete mirror -shell,which arrived this morning, I'm pretty mechanically - capable, so I'm going to to do the job myself, is there anything I have to be wary of, when doing the actual mirror swap,ie- screwing- up electrics- even though ignition will obviously be turned- off, and key removed? Thank you, Regards, Iain.

...whoops , forgot to mention- my car is a '98 LS400...... Sorry, Senior Moment! Iain.