this is from memory but most of it is common sense changed mine a feww years ago on my old ph1.
disconecct the battery leave it for bout 20 mins for airbag capacitor to discharge.
make sure the steering wheel is staight with the wheels.
the airbag section comes out first think its 2 torx from the back, then all the rings and indicator canceller come out . just unplug the yellow connetor
the steering wheel is held on by 1 big torx just undo this , the wheel will need a good bit of force to get it off, use a puller if you need to.
i take it you have the boss kit for the wheel you bought assemble the boss to the wheel then fit it, you will gwt airbag lights as you have removed the airbag i just took the bulb out of the dash. cant remember having any issues with this if you get stuck give me a shout