You can use unofficial patches with kobopatch to do this:
https://github.com/pgaskin/kobopatch-patches/pull/139
Keep in mind that you need to read all the comments, as you must change the device configuration file in addition to using the patch. Some comments also indicate that the current firmware doesn't work with this, so you also need to use a custom patch to block firmware updates, or else enabling Wi-Fi will force an update that undoes all your work. YMMV!