@Leethecat
Presumably, you have set up a 'Goodwill' fixed asset account already. If not, set one up. Then, set up an 'Amortization' expense account and an 'Accumulated Amortization' fixed asset account.
Then, create a recurring journal entry to book the amortization expense: debit amortization expense, credit accumulated amortization. You can book it monthly (~$60K/180) or annually (~$60K/15). For the first year only, you can only do a partial year amortization so you will need to determine how much you can expense based on when you acquired the goodwill.
