How do you reinforce your units (i.e replenish losses back up to full strength)?

[Gregorovitch]

This is very unclear.

[ЧPOG]

1) Manually, by opening "Replacement Troops - Helmet Icon" right pane, and buying all you need. Keep in mind that it will use logistic points depending on where this unit is located.

2) Automatically, by keeping reserve troops in your SQH - "Replacement Troops - Shooter Icon".
This reserves will be supplied only on the next turn (good when you have a lot of troops, too much to micromanage).

[流れ星]

Right side control panel, uppermost tab. Second button under the name of your SHQ. "Repl. Troops". (There's a picture of the button on page 58 of the manual. Read the manual. Seriously. It answers most of your questions.) On that screen you train replacement troops. After the end of the turn they are automatically delivered to all units in need of replacement troops. That process requires available logistics points, so if the damaged unit is cut off or the logistics system is overburdened, replacements occur only partially or not at all.

Sounds more complicated than it is. It's rather simple and intuitive once you've got it. You just order new troops and the system distributes them to the units that need new troops.