Adjust W2

You really mean you want to adjust your W-4.   A W-2 is the document you get from your employer at tax time.  You do not ever fill out or change your W-2.   You give your employer a W-4 in order to tell the employer how much tax you want them to withhold from your paychecks.   You can choose to have extra money withheld from your paychecks if you want to.  Look at Step 4 (c) on the W-4 form.  

To make changes to a W-4:

https://turbotax.intuit.com/tax-tools/calculators/w4/ 

https://www.irs.gov/individuals/tax-withholding-estimator

https://www.irs.gov/pub/irs-pdf/fw4.pdf

And...NO, you cannot claim your spouse as a dependent.  A spouse is never claimed as a dependent.  You file a joint return with your spouse; you can file a joint return even if one spouse has little or no income.

When you’re talking about making changes to your W-2 in order to get a smaller refund at the end of the year and more money in your paychecks, you’re referring to adjusting your Form W-4 so that less taxes are withheld each pay period, which would lead to a smaller refund and a larger amount in each pay check.  Here is a tool that you can use to determine how you should fill out your W-4, which you will then provide to your employer.

You can’t claim your husband as a dependent, but when you file married filing jointly, you benefit from a larger standard deduction amount.

I hope this is helpful.