How Do I Move Photo Library from my External Hard drive to my iphoto

I bought a new macbook pro and used migration assistant, like the guys at the Apple store told me to. I must have done something wrong because it set up a whole new user and put all the files, apps, settings, everything under the new user. I have the initial user I set up with my name and the user the migration assistant set up called transfer. Now I want all my photos on my user and I can't get them. I've tried copying the iPhoto library onto an external hard drive and I can access that library on the hard drive but I want to have them on my computer! When I try the suggestions I'm finding in the forums it doesn't work. I get a message saying that modifying Pictures requires and administrator name & password. When I click to authenticate and enter the password I get a message that says the operation can't be completed because backup items can't be modified. I can't just restore from a backup because I've already added other photos and don't want to loose them.

The folks at the Apple store forgot to tell you NOT to setup an account on the new machine until after you used the Migration Assistant. This is a common mistake users make but the Apple tech should have known better and warned you.

Do you still have your old Mac computer intact with all your data on it?

Yes

Yes, the old mbp still works and, apparently, I have it cloned on the new mbp as a second user also

Here's what you can do to straighten things out:

First make a Time Machine backup of your old Mac, backup everything to an external hard drive.

Next, start fresh with your new MacBook Pro: Boot to the recovery partition of your new MacBook Pro by holding down the command + r keys. Once in recovery, select utilities, Disk Utility. Erase the MacIntosh HD. (you must erase, do not install over the top of your current installation) Reinstall Mavericks via the internet from the Mac App store. That will give you a brand new clean install of Mavericks.

Next, attach your Time Machine backup drive to your new Mac. Reboot the new Mac. It will automatically bring up the Migration Assistant and ask if you wish to transfer data from another Mac. Reply yes, and select your Time Machine backup. Press OK. (Do not under any circumstance create an account on the new Mac!)

It may take a while to complete the transfer but when it's finished all your data and original account will be transferred to the new Mac and you'll be ready to go. You can then select software update and update Mavericks and whatever else needs updating.