We strongly advise people to not do it as it is illegal and your vehicle WILL fail its MOT. Numerous customers that have had engine problems due to DPF Removals and ECU re-mapping, they have ended up paying out thousands of pounds trying to rectify the related faults.
Newer vehicles have their full build specification logged on a master computer, so if the DPF is removed and the ECU is re-mapped when the car is connected to the dealerships master computer a PR Code will identify that the engine has been enhanced, so voiding the manufactures warranty. You will be breaking the law and liable to prosecution to use a vehicle modified in this way in any ULEZ/LEZ (low emission zones).