How to I make this into a WiFi hotspot without any new hardware or access points?

A sticker.

Unplug all the wires. Now it's wireless!

So, to be able to transmit packets wirelessly, it needs a medium to communicate them over. If you stick it in the microwave for a while, it should begin to absorb the microwave radiation. Once it's full enough (minimum 20 minutes in microwave, recommend full hour if you have the time), it should then start emitting excess microwave radiation that your devices can pick up, and then you can check your e-mail.

Just plug a WiFi cable and you're done.

Cut the blue wire, strip it back to the rj45 plug, and then untwist the 4 wire pairs shaping them into antenna. Works every time. You will get signal for 2 city blocks. I promise.

Drill a hole through it to let the signals escape.

Put it high up in your attic, it’ll sense the elevation and start broadcasting

Make it wireless by cutting all the cables.

It just needs more power so the internet waves come out of it, try connecting it directly to the power lines outside your house so the pesky transformer doesn't get in the way

On the phone you used to take the photo, turn on the personal hotspot.

You're going to need a radioactive isotope. I like cobalt-60 but caesium-137 can work too. Boil it into a tea. Plug one end of a patch cable in to port #6 and dip the other end into the nuke tea. Heavier isotopes give you more speed but less range, that's why I like the cobalt-60. It can punch through building materials pretty good so no dead zones.

There are already some good tips in the comments, but do not forget to remove the RF shielding inside.

after downloadmoreram.com was such a success, i guess something like wifi-hotspot as a service should exist somewhere too

hm, without adding "new" hardware you say?

• add an old wifi stick
• add an old raspberry pi 1
• stick the stick into the berry
• add hostapd package to berry
• add old ethernet calble and connect berry with the switch in the picture
• configure hostapd to mimic a wifi hotspot (thus its not "added", just mimic'ed)
• configure routing, nat, dns and dhcp server (wlan side) on berry
• configure dhcp client on berry for lan side
• use an old cable tie to tie things together so it becomes "one piece"
• connect the switch with another old ethernet cable to your neighbours internet router

tadaaa !!! turned into wifi hotspot without added hardware beeing "new"

Just open wifi settings on any device you have connected here & connect to your neighbours wifi.

Did you check the WiFi fluid level?

Take a coat hanger, some duct tape, 3 pennies, and watch s3e5 of Mcguyver.

Plug a laptop into it and enable the wifi Hotspot feature. Works well on windows/Fedora

You gotta take it near one of those 5G towers, after holding it up near a tower for an hour or twelve, the resonance from the 5G will activate the wifi capabilities.

Do you have any PCs (broad meaning) with Ethernet and Wi-Fi module?
It is possible to make a L2 bridge: Wi-Fi module in AP mode + Ethernet NIC.

You have to set the device upright so the wi-fi antenna have access to fresh air.

When the router is flat in the surface the antenna is covered and cannot breathe.