1.With the first season they added the "Directed" mode - that's what we need. Let's go solo. It doesn't matter what map, I'll play Liberty Falls





2. Open the doors and get to the church, use PaP. Let's not go any further on the quest!

At this point you will have wave 11 and it will repeat endlessly until you progress further in the story. Improved weapons easily kill enemies with 1 hit to the head - we farm critical hits.
I found a good position in bowling - zombies come from only 2 sides and you see everything, you can play with one hand:

At 11 there are only ordinary zombies and crushers - everything is simple. Once you open all the camouflages and you will need to kill the “Elite Zombies”, then just move a little further along the plot until wave 15 - elite zombies spawn there.

4.If you're tired of farming, save and exit:


5.After exiting, dont start a new game in zombie mode - your save will be deleted; when you log in, continue farming and load your save:



Points 4 and 5 can be repeated endlessly. Happy farming.

P.S. Once you have finished one gun, use wall buy or mystery box, upgrade it in PaP and continue farming.
https://steamproxy.com/sharedfiles/filedetails/?id=3373075806