All of us that have done it a few times know it can be done.Still,I would not wish the first time experience on anyone.It can be stressful.You might want to do it in stages.Is there a steel ferrule around the rear tang screw? If there is,good.As it is all in there,lined up right now,making a small job of just relieving a little around the tang,and under it,to make just a pad the size of a dime or so to locate just the tang,height and position,can be good,
Then I might come up with a, reference area up in the front reciever area,
Maybe the recoil lug area.Heck I might do both the tang and recoil lug with steel bed.I might relieve 1/16th or so.Then,I might do the same on the bottom metal.Just pads under the screws,and locating the functional datums.
JUst bring the screws to light snug,in position,held in place,but no spring on the action.Maybe .010 clearance on the mag box to reciever fit.Tape clearance is enough.
How thick do you want your glassbed?I make a little scribing gage,Make it so it wont scratch your metal,but you drag it around the reciever ,scribing a clean,uniform line.It might be .030.I suppose a 1/16 transfer punch might work.
Now I get out my carving chisels,the little palm set,I use a small,sharp gouge,and like a one tooth beaver I plunge a vertical cut just up to,but not breaking the line.Do not scoop or pry,you'll split good wood.Make each nibble a careful cut.This is roughing.Later,use a flat chisel,sanding stick,fingernail emery board,whatever,.This is the cosmetic uniform line,it might only go 3/16 deep.Now you can go back in and finish clearing the wood on down to the receiver floor.You see,as you have the tang pad and the lug pad,etc,you are relieving everything else.
While liquid Accraglass might be a touch superior,to seal and fit everything that is clearanced,I'd use gel for a first timer,It is awful to mix and pour glass only to see it start running out,leaving voids.
Then I would clean and trim a while,and do the bottom metal.At this point,the receiver and bottom metal are done,and the barrel is as centered as it ever was.
Myself,I think a pretty generous relief in the bbl channel is in order.If the forend has enough wood,3/32 is not too much.carefully gage scribe a line offset from the bbl,and carve it out.watch the line,clean with flat chisel,and I run larger sharp carving gouges down the channel,too.Sharp,you slice,not chip,split,Clean it up with round dowels with self adlesive orbitaql sander pads wrapped round assorted size dowels.
I use vinyl tape ,smoothly applied to the bbl,to make a uniform free float.Maybe only 2 layers close to the recieivr,but at leaqst 3 layers out on the forend.Test assemble and make sure you have clearance around the tape,Notouch is acceptable.
Then glass the channel.I'd use gel,and no extra fillers.Its easier.Fillers have thickness,and they make problems doing it in stages.
Be sure your guard screws a cl;earanced when you are done.