This Resonator delete pipe replaces the front res(first silencer after the flex section).

 This will be the oval Resonator approx 14" length. Suitable for OEM and MPE exhausts

5 SERIES - 540i  F90 & G30 Mod - Resonator Delete Oval pipe 

Fitting guide:

Cut the oval resonator immediately before/after the welds on each side as pictured

Slide the oval res delete pipe over the existing pipework by approx 15 to 25mm per side and tack /weld into place 

As simple as that

please see listing images for reference.