Since you have not provided year and model info, this is only a guess. On 123's and 126's there really are no special tools required. There is a bolt at the wheel end that needs to be removed and it is helpful to take the caliper off of its mount and hang it up somewhere under the fender. The real deal is to be able to move the rear end up and down relative to the body, as this facilitates removal and replacement of the new shaft. Finally there is a circlip on the end of the shaft that resides inside the rear end, which must be removed to get the old shafts out. This can be a bear sometimes. Also do not loose the spacers that are right by the circlips. They are needed on the new ones!

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1961 190Db retired
1968 220D/8 325,000
1983 300D 164,150