Yes it's possible. You have to use a third preset to host the others while copying / bounce
the main preset you want to swap.
In your example : Preset 111 to preset 123 = Copy 111 to for example 118 (or one with a "trash" sound you dont use / want) by while in 111, press RECORD (starts to blink) then press 118.
Now you have preset 111 on two places (111 and 118)
Then choose preset 123 and copy to 111 the same way (press RECORD, then 111)
Finally choose preset 118 (copy of 111) and copy to 123 ... Done .
If swapping / bouncing other presets, use the same 118 "trash" preset
every time for less confusion .....
Try a couple of times with factory presets, if you have any of them left in "Preset Mode".
Easy to recover from "Factory Mode" banks if you screw up
Cheers !