Ok, i did it !
1. Gear fluid changed. Motul 75W-90. A mechanic told me (i saw it, also) that there was very low stock oil level in the gearbox, not more than 1.5l at best !
2. Changed the gear linkages ends and did adjustment.
Its too early to say but there is change, not so incredibly big or something but there is .
The 1st seems to be better (no hard stucking for now), reverse too and shifting now feels softer.
Now, there are issues regarding linkage adjustment.
I did it by the book (Leon manual). In fact, i did it several times, last time without the seat belt, i havent seen anyone doing it and ive watched a billion of videos regarding it, although it sais in the manual that
after you put the gear lever in neutral and ensure it with the 5mm pin, you should put the seat belt around the gear lever.
Also, it sais in the manual that the cables should be
"inserted, free of tension" meaning inserted in the cables (the way i got it!) so i was trying not to let the cable go out from the ends while locking them. Contrary, a Dieselgeak guy in his manual for VW's say that you need to pull put the slack from the ends (not sure what slack means, only guessing) but he was pulling the cables on the other side, towards the windshield! Totally opposite than i did. In his other video, he doesnt do it at all, pulling cables at all, just unlock and lock them again.
All in all, i now know
how to do it, even without moving anything under the hood so i can play but i am wondering which is the best method as i would like to do it and forget abot the damn gearbox!!