Fitting An Awkward Oven Seal

[DuzyEverwork]

Hi we live in Spain and I have a Corbero oven (Model 6054VT if that makes a difference) and the flippin seal is different to every other one you can find fitting instructions for on the internet.
It looks as though you take the oven door off (which I do when I clean the oven) then you undo four screws at the far corners on the oven itself and the 'picture frame' of the oven mouth comes off and releases the seal, nothing so simple as fitting it with clips at the corners or anything like that. Does that sound sensible to anyone on here, have you experience of it, should I go ahead and try or just spend gallons of euros and get an engineer out?
It poss could you point me to a link showing how it's done, the last thing I want to do is take it apart and have bits pinging off all over the placehanks for any useful info you have.
Saludos.