I can probably hit the high points and get you going with it.
RFS - Relative Field Strength, raise the internal antenna and take readings around your transmitting site to check antenna pattern (nothing needs to be hooked up).
MOD - Modulation - It can only be used while using the internal dummy load and is therefore limited to radios 50 watts and under (the internal dummy load is rated @ 50 watts). Disconnect any external antenna, turn dummy load to ON, hook up radio to TRANS., set SELECT knob to CAL and key the mic, adjust the RF LEVEL knob to 100% modulation, set SELECT knob to MOD and check modulation.
RF POWER - This one can either be used with the internal dummy load or with an antenna attached. Set SELECT to RF POWER and RANGE to one of the wattage levels and read output wattage.
SWR - Make sure the dummy load is OFF, and your antenna is connected set the RANGE to FWD, key the mic and adjust the SWR CAL knob for the highest reading on the SWR scale which is 30. Set RANGE to REV and read the SWR of your antenna.
I think that should about cover it. If you have any more questions, feel free to ask.