Samurai reverse & 5th do not go in

Hello, I’m new here. Hope I’m at the right corner. I have a Samurai Santana Van (Bj.93), in which the screw has been broken again and again for some time. This was changed in about a quarter of a year 3 times. But now the reverse gear and the fifth does not go in again. I have to use both hands to switch the two gears at all. In the workshop I was told that the attachment on the drive could be switched. e, which can be unscrewed from the interior of the vehicle, be worked out. I think it’s called a gear lever. However, I can’t quite imagine that this should be all of it. I would be grateful if someone had an idea, because I’m animally into the thing. And to the people who always say, “Buy a real car!” I don’t want to do the favor so fast.