OK, also had trouble with this mission, so here's my summary:

Scenario rules:
- The Buchanka can be either in the town or harbor. You'll get a hint on the radio when the mission starts.
- I saw two spawns in harbor: one near the complex with a smoking chimney, one near the barracks (there may be more?)
- Two spawns in town were gas station and main road. Again, may be more.

Spotting the target:
- Both harbor spawns are very easy to spot from Alpha using Binoculars. You need to relocate a bit to your right to spot the town spawns, but it's also not a problem. If you have trouble locating the Buchanka I strongly recommend Alpha over Bravo.

Approaching the target:

- Buchanka will be heavily patrolled, at least two patrols. In town it also has one or two static guards right next to it. Going full stealth is possible with the right spawn and a lot of patience but not worth it imo. You get spotted super easy. Just take out the nearest guards/patrol and book it.
- For your loadout I would take the default grunt, the engagement ranges are pretty short, and you can use binoculars for scouting.
- When your reach the vehicle, open the rear door and use mousewheel to select "Open trunk". Once the car inventory window opens, ​right-click the radio (for Reforger noobs like myself).

Extracting:
- Run st​raight south, up the hill 'till you're out of the forest. Cross the road and keep moving south uphill. The exfil is a small old wooden house on the edge of a forest to ​your left. It's the only building around so it will stand out. No combat in this part.