Hello and very welcome - Rajko !
First : Because of removing the rearspoiler from the other decklid - there are only two little screws - on the right and on the left foot of the spoiler - at all four feets there is double sided tape to hold the spoiler .
After removing the screws - you can (carefuly !!!) use heat - maybe a hairdryer, that helps to solve the spoiler - or, you can use a piece of welding wire to cut of the double sided tape underneath the spoiler

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So - it´s realy no bigger problem to remove this .
Second : What a lot of work, that goes into your "Lemon" - I know about all that welding work, to fix the rusty body of an old Daihatsu ... well done !
I realy love yellow colored cars

- and good to hear you also have rebuild the whole technical part of the car - I think, the Cuore will stay alive for a long time, now

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We looking forward, to hear and see much more of the Cuore rebirth !
Greetings from Mo .