how to remove unused apps from Iphone

If you have a 6S or later touch an icon lightly (rather than pressing) and it should jiggle. If it doesn't go to Settings/General/Restrictions. If it is on enter the Restrictions password and you will find that you have disabled deleting apps.

This no longer works. They don't start to wiggle and show an X anymore when you hold your finger on it. So now what??

The native apps cannot be removed. For the apps you have installed try tapping and holding the app, when it wiggles click on the X.

Delete music, movies, apps, and other content from your iPhone, iPad, or iPod touch - Apple Support

Click the link and navigate to the instructions found under Apps.

You cannot delete default apps from your phone. You're welcome to hide them away in folders if you're concerned with clutter.

Arrange the apps on your iPhone, iPad, or iPod touch - Apple Support