You need to use a counterholding wrench on the rack gear to prevent it trying to rotate as you apply torque to the inner tie rod ball joint. That is the "movement" referred to. There is a flat milled into the rack near the driver's side end to accommodate a counterhold.

Also, there are deformable locking washers where the inner tie rods attach to the rack gear, and these should only be re-used if in very good condition. Any signs they were previously removed and then peened over again means you should get new ones. Major safety item.

If it were me, and the rack is tight and a non-leaker, I'd disconnect at the outers, marking the rods, and counting turns, and then perhaps get a professional alignment - which the car may benefit from anyway. I would avoid putting a wrench to a good rack.
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Bob: Son's XC70, daughter's 940, my 81 and 83 240's, 89 745 (V8) and S90. Also '77 MGB and some old motorcycles