Dear Onkel Udo II,

Hope you're well. Why not use a thin cutting wheel to split the tie rod end and the lock nut? Two cuts - parallel with the tie rod's axis but not down to the tie rod itself - might then be finished by use of a cold chisel. Splitting the tie rod end might allow the tie rod end to be turned.

Plainly, there's some risk that corrosion has ruined the threads at the end of the tie rod. If, however, those threads are in good order, then new tie rod ends could be installed.

Hope this helps.

Yours faithfully,

Spook