Since you have the desktop XYM wallet do this.
Go to accounts. You will have one seed account ( you picked this when you fired up the XYM wallet the first time for the opt in drop) Copy that address.
Have the opt in account selected from accounts, then go back to home, this makes the opt in the account you are USING. It should show your XYM Balance there.
About dead center of the screen you will see ^Send. Click this, it will have your opt in seed account 1 as the from account, enter your copied NEW seed account address into the To section.
Add a test message if you like, send a small amount to test, then repeat the process and send the rest over to the seed account.
you will see green bars in the upper right hand corner saying you started a transaction, go back to accounts, choose the new seed account and go back to home, watch for the green bars there.
Click the Exploer on the top bar on the right, click transfers and you can watch your wallet show up and process the transaction.
I hope that helped. I’m stepping off for a bit so I wont be here for replies for a bit.