First of all let me first be clear on your bike, its a 2 Valve per cylinder 1100?
The 2007 GRiSO I have has only 1 Start relay, no Maintenance Relay
Your Step 1 is correct the existing wire is too small to support the 40 - 50 Amp inrush current the solenoid needs. There are two coils in the solenoid one draws 40 Amps but just for a split second. Instead of changing the wire in the relay base you can just cut it close by and join the larger wire on to the small tail, the other end of the new wire gets a new spade lug of course.
I don't think you need to do step 2 but if you have a voltmeter or test lamp just make sure that terminal 3 or 5 in the relay base is alive with the key OFF.
the 2007 I have already had the direct feed to the relay however you might need to upgrade the wire, a 20 Amp fuse for sure.
I didn't bother upgrading the relay feed wire on my 2007, with just the wire from relay to solenoid the starter engages 3 x as fast as before.[You must be registered and logged in to see this link.]
If you do replace the wire from fuse C to Start Relay terminal 3 don't forget you must also feed the Injection Aux. Relay
This is an alternate way of doing a fix for anyone reluctant to start cutting wires
A new relay is supplied direct from the battery, the relay coil is fed from the original trigger wire.[You must be registered and logged in to see this image.]
Note how I have drawn the solenoid with 2 coils, how it is.
The 20 Amp fuse can be fed from the battery post but there are already too many wires there so I show it fed from the large hot terminal at the solenoid.
If the relay is located next to the starter the fuse leads should reach without having to extend them, Dont use a relay base just use spade lugs direct onto the relay pins.