I am replacing my original DJI Phantom 3 Professional with a new one (due to a crash, bummer!)
I will be using my existing Mini iPad 2 and my question is do I delete my original DJI GO app and reinstall for my new P3P and how do I save the information/log pertaining to my first and now useless quad??
Also, can I still use my 1st battery as a backup for my new P3P?

Any help would be appreciated.

I am replacing my original DJI Phantom 3 Professional with a new one (due to a crash, bummer!) I will be using my existing Mini iPad 2 and my question is do I delete my original DJI GO app and reinstall for my new P3P and how do I save the information/log pertaining to my first and now useless quad?? Also, can I still use my 1st battery as a backup for my new P3P?

No, do not delete the original DJI Go app. Leave it as is, and use as you did before.
To save the information from your first Phantom, open the Flight Logs in DJI click the cloud icon and Sync. It will sync all records to the cloud, this is independant of your old quad. When you use your new one, it will add to the totals for your user account, but a new 'device' will show in the overall list.
Your old quad does have detailed .dat flight logs on it, but you probably won't ever need those and can forget about them.
Yes you can still use your first battery as a backup.

digdat0 Posted at 2016-6-16 02:24
No, do not delete the original DJI Go app. Leave it as is, and use as you did before.
To save the  ...

Thank you digdat0.  You have been very helpful.

Hello sigmahat, you can simply sync all the flight record via DJI Go.Then they will be saved in the cloud.As for the battery, if it isn't damaged and works as normal, it can be a backup.