How do I turn on HomeSharing without original remote? Accidentally the Apple TV had its home sharing turned off (device used was the remote app on iPhone).

The original remote is lost.

Have Apple Mac laptop and HP Laptops also iPad 3rd Gen, and iPhone 5s available.

I have looked up answers but it suggested that I disconnect Apple TV, and connect it to my laptop. Restore settings etc. It seemed like a reasonable work around. Only thing is I am not sure how I am supposed to connect it to a laptop. my question is HOW?

All answers seem to suggest that it's wireless but I don't see how this is possible when Home Sharing has been turned off.

HDMI cable didn't work. Ethernet didn't seem to do anything either. But I maybe I'm just looking in the wrong place - or just doing it incorrectly.
The Apple TV should be connected with a mini USB cable to your laptop USB. 
Go here: http://www.howtogeek.com/214243/how-to-factory-reset-or-reboot-an-apple-tv/ and scroll down to "If Your Apple TV Will Not Boot"

With laptop(and running iTunes) connected to Apple TV plug in the Apple TV to power. 

"If your Apple TV will not boot properly, or something has gone wrong and the unit isn’t operating properly, you can almost certainly restore it by connecting it to your PC and using iTunes to factory reset it.

First, unplug your Apple TV. You still need to power it back up, but before you do that, make sure to plug a mini USB cable in the back of your Apple TV (right below the HDMI port) and then to a USB port on your PC."

The link above even has pictures.