If i have submitted my 2019 tax through paper filing (since first time so paper filed), and got returns. I have W2-C and need to submit amend. How can i do that?

A 2019 federal amended tax return, Form 1040X, can either be printed and mailed or it can be e-filed.

See this TurboTax support FAQ for amending a 2019 tax return originally completed and filed using TurboTax - https://ttlc.intuit.com/community/tax-topics/help/how-do-i-amend-a-2019-return-in-turbotax/01/1238456

I believe you can only efile the amended return if the original return was efiled.  See the blue box at the top of this

https://www.irs.gov/forms-pubs/about-form-1040x 

Depending on what the W-2C was for, it might not be necessary to amend at all.   Often W-2's are corrected because of errors on lines 3-6 or line 12 or other minor errors that have no affect on the tax at all and only needs to be reported to the IRS by the employer with the W-2C that the employer sends to the IRS.   Most of those items do not even go on your tax return at all.   You only need to amend is the change affects the amount of tax owed or refund amount.

And if a small amount of refund then it might be more hassle and expense to amend and mail then the refund is worth.