Welcome to HM!!
I hear your frustration!
The first time I did this, it took several hours.
Looks like you have a round column mill.
Regardless of round or square column the process is the same.
Note your round column is different from my #3000 Cincinnati Vertical which . Which is different from a Bridgeport design which has a "nod" (front-back ) adjustment. The nod feature is both a strength and weakness of a Bridgey.
We need to think about the three different axis to adjust. The round column has fewer built in adjustments. Thus only leaving us with a vise adjustment left-right relative to the spindle. Eventually you may want to check out:
http://homemetalshopclub.org/news/13/tramm_presentation.pdf
I hope the above wasn't overwhelming. I certainly had difficulty thinking in all three dimensions.
Do you have an indicator or gauge of some sort? Really doesn't need to be a specialty gauge. Any accurate gauge will work. However, specialty gauges might be easier to use.
There are alot of great videos on the inter-net. I'm pretty sure I've watched all the Tubalcain (Mr Pete) videos at least once, and more recently all the Suburban Tool videos (Don Bailey). There are many other good videos as well. All free of charge.
If you don't already have an indicator and the apparatus to hold it you'll need to acquire one. You'll want it for other things anyway. You don't need to spend huge dollars on these. Although you may eventually want really good ones of different design and increments. There may be members here at HM who have extra laying
Then please check out this Suburban Tool video:
You will note that Don Bailey uses an Indicol. I use a piece of round stock held in the collet.
Note that he is discussing all three dimensions. Initially, you are likely only concerned about the vise relative to the spindle, although you may eventually want to work on shims to manipulate the other planes.
Please watch the video and acquire an indicator and the necessary apparatus, then rewatch the video.
You can do this, and have fun doing so.
Please check back here, and update us on your progress or frustrations!!!
There is no stupid or bad question.
We've all been in your work boots.
Daryl
MN