Q: How to change from 2lt engine to a V8 please?

Basically, you will have to change just about everything in the drivetrain and there will be quite a few places to reinforce since the vehicle was designed to handle the torque output from a 4 cylinder engine. This swap is a bit specific so you will have to do a lot of the research yourself to find the right parts and probably work through some trial and error before getting things just right. The engine, transmission, driveshaft and rear end will have to be upgraded and more likely than not, the electronics in the mazda will not support the electronics that need to be run on the engine for it to perform properly. The engine computer from the mazda won’t be able to run the V8 and the same goes for the transmission. The mazda transmission will not likely bolt up to the range rover v8 and if it does and the v8 works, the power from the v8 may cause damage to the transmission that was designed for a 4 cylinder. There is a lot of work and research to be done here.