2.5 mm Nut Loctite to socket

Did you try some solvent or heat? I would cover the plastic parts to prevent damage either from the solvent or heat.

@drfusion3000 get a long screw that fits the thread of the nut. Screw it in and get some locking pliers. You can use a second pair of those to hold the driver. You now have more leverage. Now you can try and apply some heat. A heat gun will be needed since a hair dryer won't supply enough heat to loosen loctite. Depending on which product you've used, you are looking at temps around 325F for the standard (BLue)loctite and 500F for their better threadlocker (Red). Use the "screw extension" and the locking pliers to try and pull the nut free,

If it still won't budge (or you can't apply the heat), there are commercial adhesive solvents available, that will even take care of loctite products. Something like Acetone or MEK (Methyl ethyl ketone) solvent will work (depends on where you reside, it may be unavailable), as well as a commercially available Super Glue Remover (most departments stores sell the Goof Off brand). Loctite itself sells a remover (LOCTITE SF 7601) but it costs a fortune :-)