As MJ has said regards DPF if you gut it all should be fine regards the mot,as it's just a visual check and an emission check.
Best to go with a reputable tuner for this as the regen cycle will need to be de-activated properly otherwise you could be in for a lot of issues.
Bassically a remap will be needed after the DPF has been gutted and the tuner should remove the relative DPF software.