T440s with Windows 8: How to do clean install?

[DEAF]

Hello everybody. I am just new here, and am going to be a new ThinkPad user. I just brought a new T440s off eBay for less than $700. Here's the specs:

Dual Core i5-4300U
12GB RAM
500 HDD
16GB M.2 SSD
14" 1600 x 900 HD+
Windows 7 Pro 64 Bit with Windows 8 Pro License (Windows 8 is currently on T440s)
3 years of Warranty

I want to install 250GB SSD to replace 500GB HDD. Do I have to update everything such as drivers and BIOS before I install SSD and then do a clean install? I'd like to install Windows 8.1 as well. As far as I know, Windows 8 is currently on T440s (the seller used the Windows 8 disc recovery or whatever it is called, and T440s will arrive this Monday). Does it count as an installation DVD? I am not quite sure if it's 8 or 8.1 DVD. Once I receive it, is there a way to check if it's 8 or 8.1? I've been using Windows 7 and older versions, and it's time for a change. I've never installed SSD and RAM so I'm new to this whole process so please bear with me!

If you can provide the step-by-step guide, that would be great. It doesn't have to be detailed, just be brief.

[sktn77a]

Unless you have a touchscreen, I think Windows 8 has the worst user interface imaginable. The actual OS is worth having, but only if you install a different user interface (such as Classic Shell). You will get Win 8 on the computer, which can be upgraded to Win 8.1 from Microsoft for free (it's basically as "service pack" - bug fixes that should never have been there in the first place!)

You can delete most of the Lenovo apps, if the original install was from a Lenovo image and the apps bother you. Personally, I find them useful. You can also create a set of backup DVDs if you so choose.