I don't know about a 94 roadmaster, but on my 95 lesabre, i had to take the HVAC vents out first. Pry up on the bottom of them (very gently!) and they should pop out. There were screws holding the dashboard in behind where the vents used to be. Assuming you are removing the dash to install a new stereo or climate control unit, they all "pop" out. No screws. Best to throw the car in neutral once you are done pulling out dash as to slide dash cover out.
You'll need to take the fuel tank down, but you have to be careful to disconnect the wire connection on the top of the tank before it comes all the way down.
Take a look at the front of a 1949 Buick Roadmaster. That is a waterfall front end.
Their are screws at the bottom of the dashboard start from the driver side and go right their mite be about 6 screws
take out the bolts
you have to take out the whole dashboard
Take it to a body shop.
Remove the wheel(s), remove break caliper (set aside on a block of wood so that the break line doesn't take any stress) then simply pull off the rotor and replace with new rotor. Installation is the reverse of removal.
Remove retaining nut
you have to take the timing chain off
You MUST state engine and year when asking questions like that.
It takes 5w30. Use synthetic blend.
10w30 says it right on the oil cap.