When can I complete Mincemeat?

You do not have to wait for the third area. Clear the first wave, open the next area and go to the trap position after the trader.

What if the Zeds will not step into the trap?

Attract them to the spot, run quickly to the lever and use it.

Events & Seasons

KF2 Mincemeat - Kill a Zed with the Woodchipper on Krampus Lair

A short guide to the Mincemeat objective of the 2017 Krampus Christmas event: kill a Zed with the woodchipper trap on the map Krampus Lair. The author says it is easier than people think. For the whole event see Krampus Christmas 2017 objectives.

Steps

Do not wait for the third area. Clear the first wave, open access to the next area and move to the trap position, which is after the trader.
Wait until a Zed appears near the woodchipper.
Press the action key at the lever the moment the Zed is in position.

Woodchipper position The woodchipper area after the trader.

If the Zeds do not want to be killed, lure them to the trap, run quickly to the lever and pull it.

A route variant with arrows is described in the full objective walkthrough ("Mincemeat" section of the event guide).

FAQ

When can I complete Mincemeat?: You do not have to wait for the third area. Clear the first wave, open the next area and go to the trap position after the trader.
What if the Zeds will not step into the trap?: Attract them to the spot, run quickly to the lever and use it.