Not all will agree I'm sure, But here is how I do it and it works well on the grizley's too. I'm a retired welder with lots of various hand grinders in the shop. I use a "well worn" ie. slightly rounded and very soft sand-paper disc. "Napa" caries these in their welding supply section in various sandpaper grades these are not flat discs and are used to polish welds[ I like the finest grade I can find], they are pieces that overlap each other like the pages of a 1/2 opened book. [Hope you can get what I'm trying to explain]. I then place my 4 1/2 grinder in a vise " Disc side up" turn on and lock the button on. Be sure its in vice securely. I then start pulling the broad head back from back of broad head to the tip of buy holding shaft at an angle that will just very slightly allow the sander to touch the ferrel on the BH. I use this very slight touch to the ferrell to get the correct angle [NEVER go so far as to actually grind into the ferrell] Do this equally to each cutting edge of BH on each side until you get the ange uniform all the way down to the actual cutting edge. This will actually be pulling back the factory angle to one not nearly as sharp. Its pretty easy to also pull back the tanto tip angle in this manner also. After this is done I touch up both sides with a diamond lap to smooth and allign any burs left from the grinder. Once this ange is obtained it is very easy to maintain in the field with a small 6-8" bastard file [I use a Nicholson] don't file too hard and soft stroke neard the end. Shoud have also included I dip the BH in water often during the grinding as I'm very careful in maintaing the hardness of the head by not overheating it. If this is "Clear as Mud" call me and I'll try and explain it a little better. My ph# is 360-989-6355. Hope this is some help.
Gene