First, don't alter a collectible rifle. There are some MNs around that were snipers, and were converted back to standard service rifles. Altering one of these is more restoration than anything else. If you check Claven2's posts in the Milsurp section, you will find a detailed description of this process. Repro scopes and mounts are available, made in the former Soviet Union. If you do not want to alter the bolt, you can buy bolt bodies already converted to sniper configuration. Have a look on eBAy to get an idea of what is available. PU scopes - the short ones - use a sidemount on the left sidewall of the receiver (round, high). The long PE scopes mount on the top of the breech.
You will need to drill and tap two holes in the receiver, drill and ream holes for a couple of pins, fit the base to the receiver, inlet the stock for the base, alter the bolt handle. Approximate windage is achieved when the mount is fitted. Crude elevation is obtained using adjustments in the base. The PU scope moves the crosshairs, not the image, so you want things lined up pretty well before you start using the adjustment knobs.
I wanted a simulated, economical sniper for range use. Considered a MN/PU project. Instead bought a bubba'd 03A3 Springfield, which already had holes in the receiver, installed a Weaver 330 scope in Redfield mounts. Currently waiting for stock hardware, and some other bits & pieces. Total cost will be less than doing a MN version. It will resemble an 03A4 pretty closely, and I'm already set up for .30-06.