Missile skid turns?

Recently I've been reading about the UK BVRAAM project.

One question really:

Originally it had four mid-fuselage wings for manoeuvrability, now it has
none. This seems a little odd, since it makes sense that the more agile
missile will have a greater number of control surfaces.

Since then I've found that the new design shall use bank and turn at long
range, and in the immediate short term prior to the kill - skid turns. How
do you skid a missile at 2M+? Exhaust deflection? If anyone can explain, I'd
be very grateful!

Cheers,
Jim Doyle