How can I change the prefilled amount of my income? It varies from my actual W2

By using your keyboard to key in the correct amounts.   Good thing you caught the mistakes----if you import or take a photo of a W-2 you always need to double check the entries.

If you are unable to correct your W-2 amounts using your keyboard as xmasbaby0 has described, you can  manually edit your entries for your Form W-2 in TurboTax as follows:

If you are using TurboTax Online/Mobile: you can use this link W-2, or you can:

1. Open your return.
2. Go to "wages and income"
3. Under W-2's select "Add/Edit" next to your W-2 that you need to edit.  (See the screenshots below for additional guidance)

If you are using TurboTax Desktop:

1. 1. Open your return
2. 2. In the Search bar, enter "W-2" and select the "Jump to" link. This will take you to your W-2 entries 
3. 3. Select the (down) caret next to your W-2 and then select "Edit"    (See screenshot below for additional guidance)

Turbo Tax Online will look like this

TurboTax Desktop will look like this:

Click here for additional information regarding editing your Form W-2.