How do I install those delta update file if my Recovery is in TWRP?

Since I have previously rooted the phone and bring it back working after unbricked it by `adb sideload UL.zip` from Asus (the official ROM)
now I want to update to V 2.20.40.63 (http://forum.xda-developers.com/zenf...5#post62580081), but TWRP won't let me install it, not even adb sideload, what are my options to get it updated?