$2000 of unearned service revenue is still unearned at Dec 31st do I subtract 2000 from the unearned service revenue on the original balance sheet to get the adjusting entry because its still unearned?

You Subtract a amount from your beginning Unearned Service Revenue to get to the ending amount of $2,000 in the Unearned Service Revenue Account.

For example if there is a beginning Unearned Service Revenue Account has $10,000 then you do an $8,000 adjusting entry to reach the ending balance of $2,000 in the Unearned Service Revenue.

The adjusting entry is:

Debit Unearned Service Revenue for the Amount.
Credit Service Revenue for the Amount.

Sooo if the beginning balance for unearned service revenue is 3100. And 2000 is still unearned would u debit unearned service rev for 1100 in the adjusting entry?