R&R _? Ground wires on mast head at keel_rusted, poor connection.

[Verne]

FYI - just did a new bottom job on Deja Vu, 3 gallons of SeaHawk, two good coats, bottom was in great shape, almost too good to be true,,,, been 3 years.  Installed new temp and oil sending units with new Stuart matching gauges, running plus 50 on oil pressure, this is good news, thought I had a problem.  New thermostat, and engine wise, I think I am finally dialed in correctly. 
NOW - new concern,,, of course.  I noticed the ground wires on the mast step area are very corroded, almost no heads on the bolts.  What is the best way to repair and replace these grounds?  I have no money left to pull the mast, so I need mast in boat repair method. Can I cut - aka grind - these old rusty ones off?  Drill out the old bolts, or I was told they might be lag bolts... and re-drill one over in size, tap and die?  Active project, could use some quick advice, please.
Verne
Deja Vu - Cutter 367 Hull# 22
251.753.5177 cell

[P69]

Verne,

My 367 (hull 42) had the rusty lag screws also. Three came out with vice grips on what was left of the threads (heads long gone). One stayed in, ground flush.

Not sure if you'll be able to drill them out without the bit slipping off into surrounding soft material.
Does your boat have an aluminum step with slots? Maybe you can put in some new ones fwd or aft of each, into the existing slots. Maybe you can just put another set of screws  in new hols through the step, into the keel. 

Here are some recent threads on mast steps

http://www.pearson365.com/forum/index.php?topic=1709.0
http://www.pearson365.com/forum/index.php?topic=1764.0
http://www.pearson365.com/forum/index.php?topic=1160
http://www.pearson365.com/forum/index.php?topic=113.15

[Verne]

I think I do remember two aluminum stepped slots - I was told, they act like a kind of washer?   Mind if I pop a few pictures, then place them in this thread for review and comments?  If I thought I could just cut the old wires, clean and place new lead ends on wires, and then drill new holes for bolts, that would be a sweet and simple fix. Any reason I can't just do that?

[SVJourney]

As far as the grounds go, it would totally fine to drill and tap a 10/32 or 1/4 hole and just attach the ground to the step.