I know a small amount of WD40 on disks will burn off with use, but if it has soaked into the pads, you probably need to replace them. Oil contamination of pads is notoriously difficult to remove.
cracking effort dont worry, that wd40 gets everywhere, lesson learnt. cover up the discs, or better still dont spray in those areas and apply with a cloth.
get some brake disc cleaner and liberally apply to the disc and clean it off (best up on paddock stands so you can spin it properly).
not a bad time to clean the inside of the caliper too. have a look at the pads and see if they actually have a coating (you dont need to have much wd40/lubricants on there before you’ll lose you braking so might not be as bad as you think). be careful not to pop the caliper pistons (did this by accident on the last track day, aggravating!)
clean them off if so and maybe give them a light rub down with some fairly fine sand paper (just try to ensure you do it evenly).
disc shouldn’t really need it but fine grade wet and dry to take off any surface residue.
also bear in mind the brakes may need to bed in again slightly if you do the sanding route
If you have soaked the pads there is no way to get them clean again as the pad material soaks oil up like a sponge as its full of minute holes. The WD40 will continue to leach to the surface with use.
If its just a light coating you may be ok but is it worth the gamble?
doubt they’d have soaked from just transfer from the disc from overspray but agreed otherwise Chunkythe other question jovie is how many miles have the pads done/how much wear is left in them anyway? if the’re already through most of their life then you’re not saving much money in salvaging them (and how much you use the back brake for that replacement too)