Hi

I'm a medium DIYer and I did this operation. I replaced all the rear control arms arms by replacing each one in turn. There is one tricky arm where the bolt looks too long to go back in the hole due to the confined space (I can't recall but you will know it when you do it). Just use a lever (big screwdriver) to push it in. Otherwise I would say from 1 to 10, a 6. It is very tedious work with all those bolts that need torquing. Please be careful in placing the jackstands as you will be pushing and pulling those wrenches quite a bit.
Front tie rods are easy if you have a tie rod breaker tool. I used the screw in type rather than the pickle fork. Replace also the centre connecting rod and while you're down there, the idle steering arm bushings. Maybe 3/10.

Finally you need a 4 wheel alignment. Oh yes, the bolts need to be fully torqued while the car is on the ground to settle them down. Otherwise a wheel alignment can go off if they start to settle after the alignment.

Good luck.

Regards
Oreo

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1992 124 E200 (Euro)