Pretty simple, actually, how they work a "get around" on the 13th amendment. Even though they call it a draft, every single guy that was EVER in the military was there by choice.
Sort of like how they do the "voluntary" income tax in the 16th.....everybody KNOWS you have to pay 'your' taxes, right ??....even though it's not a DIRECT ( apportioned ) tax, nor an INDIRECT tax as the Constitution requires....and the Supreme Court long ago said "The 16th gives Congress no NEW taxing power it didn't already have".......the fact that the 16th says "Congress shall have the power to tax income" didn't say that some NEW power outside the DIRECT method suddenly got created, and all graduated income tax laws are NOT Constitutional because they don't comply with the requirement to either be a Direct Tax or an Indirect Tax......nah....forget that little technicality and just volunteer your dang taxes, BOY....because EVERYBODY knows you owe taxes....ahahahaaaaaaa ( You make think I took a right turn on taxes here, but you'll see how this relates below )
Here's how it works on the "draft":
You are required to raise you hand and take the oath of enlistment...."supporting and defending the Constitution against all enemies, foreign and domestic" ( Yeah.....what a joke THAT is, huh ? ). You can't get in the military without doing so.
When that point comes, simply step CLEARLY, and VERY OBVIOUSLY to one side, and refuse to do so.
Better still, just don't even get in the group of "standee's" to begin with....when they holler "OK....ya'll all come stand up here for the oath ceremony".....just don't.
They have no authority to ORDER you to do ANYTHING at this point...you complied with the law requiring you to "report" for induction....but you DON'T take orders from the military AT THIS POINT. Unfortunately, people, not being all that much different from cattle, will pretty much do what they are told when they are told....they don't think, they simply go with the herd.....resigned to their fate.
They will cajole, holler, do everything in their power to get you to do this, get you off in a room alone, and you'll likely have some BIG drill sarge looking guy in your face for a couple hours insulting you and your entire family lineage, but unless you "volunteer" at THIS point, you won't go in the military.
99.99% simply do so because some big guy in a uniform said "Raise your right hand and repeat after me".
"Quaker Up" at this point, and STAY THAT WAY, and when they finally figure out you ain't budging, you'll go home.
I saw a guy do this when I went in during the Vietnam era.....and he WASN'T on the bus to basic training with the rest of us ! Very few 18-19 year old kids have the presence of mind to know which way is up....and that's WHY they make excellent cannon fodder.......but some do. Especially IF they had a slight bit of coaching on what the deal is, and how it goes down.