Question about installing Lion to a new internal HDD.

[RedEyedDream]

I just got a brand new internal 2.5" internal hard drive for my MacBook Pro. I have OS X Lion on my current internal hard drive. When I go to the App Store to try to redownload the installer .app it doesn't let me. I also could use an external hard drive, as I have one.

So that leads me to my questions.

Is there a way I can redownload Lion from the App Store so I can install the OS to my new HDD after install

or

Should I use Time Machine to back up my current hard drive, install the new HDD then install the Time Machine back up onto it?

 

[RKO]

Click on purchases in the App Store press option and click on Lion.

 

[RedEyedDream]

When I do that it brings it up as I would have to pay for it again? I don't want to pay for it twice.

 

[RKO]

When you click on it you will be told that you have already purchased it before and if you want to re download again after you authenticate. You won't be charged twice.