Thank you all for your advice and comments.
I've had an exchange of emails with a fellow Apuger form Finland, and he suggested the same as Loose Gravel.
The only point is to unlock the eyepiece retaining ring, with a suited wrench or nose plyers, and then the cover opens up.
The fix, once open is just about glueing or taping the loose connector, and can be done quickly.
Having it repaired by a repairman would take a long time over here, and this meter is so helpful !
I'll update this thread later.
Cheers,
Marc