How to CLEAR a text conversation with iOS 7?

I have an iPhone 4 and just updated my software to iOS 7 last night. It's a big change. I used to be able to go to a conversation with someone click edit, then clear all. This would erase my texts with the person but not the actual contact of them in my messages. I know this sounds dumb and confusing but I would really appreciate any help!

How to get my iphone 5 out of recovery mode whitout losing data?

How to get my iphone 5 out of recovery mode whitout losing data?

Added (1). I was updating my iphone suddenly my itunes on computer gives me a error and my iphone show me the sign of itunes with a usb cable and i open the itunes later and give me a message that i have to restore my iphone

What can I do about iOS 7 draining my iPhone 5 battery? - 1

I changed certain settings that would prevent the battery draining from too much and looked online for several more, it made a difference but the battery percentage decreases a lot more than it used to (even if I'm not using it for a little over an hour and no apps are running, it will go down a little). If apple is fixing glitches and bugs with it, will it fix the battery issue automatically and how long will it take or what can I do?

How to restore icons after ios 7 download?

Downloaded ios 7 onto iphone and now all the icons from App Store have disappeared from screen. I can only access them though the App Store under 'Updates' They are all up to date. I can't find a way of uninstalling them and then re installing. I have tried a new app which has displayed as usual but can anyone help with all the others please?
Janice

Added (1). Tom - I had tried restarting and just tried it again - no luck I'm afraid.

IPhone 5 on Sprint network with iOS 7 saying that I have Invalid SIM?

Can I still use my phone? How do I get it to work? I haven't done anything to my phone- all I did was download iOS 7.It is not jail broken and I didn't have iOS 7 beta or anything. It says "invalid SIM" where it usually says Sprint and the dots showing my signal strengthand I don't even know why. I've got LTE and unlimited data if that has to do with anything. Can someone help me get my service back?