It can all be fixed from inside the car besides the selector linkage bushes. Take off the gearknob. Take off the transmission tunnel plastic, that should expose the ball joint at the bottom of the gear lever. This is held on with 3 screws, take the screws out and the gear lever will lift out. You'll either have a gear lever with a solid metal acorn on the bottom or one with a plastic acorn. The metal types have a bush inserted into the selector lever. This can be changed from above with the gear lever out. On the plastic acorn types, the acorn wears and falls off. A new gear lever will fix this.
If it's selector linkage bushes, these are accessible to at least assess their condition from under the car by reaching above the prop shaft.