No special technique, it will lose its memory of the datum only. Following the instructions exactly will reset the datum, if you get it wrong i.e. the lift over runs or stops short even then you have programmed wrong. You would need to disconnect battery and re-program datum again.
If I were you while you do have some power take the lift to the top charge point and mark with a pencil on the charge points where the plungers finish and then when you re-program you will get it exactly
You can as an alternative change them while on the charge point and you may get away without a program if your quick but I change batteries a foot off the top charge point so it’s a two minute job to program after.
