wen u say u have removed the amp, ahve u taken the wiring with it??? because the amp'd systems had a diff ISO compared to a standard ford system, urs would usually use a scart type ISO, thus givin the amp the signal for sound. if u have removed it all, u shud b able to bring a wire frm the amp to the bk of the head unit, and then use a standard ISO, but thats pure theory, im only guessin at present. if u cud sort pics out of wot uv got i cud wrk it out 4 sure (neva wrked on a cossie before, just mondeos with similar spec systems)

as for the headunit, its just a matter of gettin a bit tough with it, push the removal pins in on each side, pull them outwards away frm the unit. then its just shake frm side to side, and it wil eventually free itself.

if u have any specific issues and can describe them to me, pm me or sumthin, i used to fit stereos (for halfords admittedly, but i was self taught, so their 'training' did not dumb me dwn and cause me to break evry stereo i touch )