This in not only do-able, it's quite common.
You will pay tax on the conversion amount. Depending on how large your IRA is, and where you sit relative to the tax brackets, you may want to consider doing this over several tax years so you don't pay more tax than is necessary.
There are no penalties for doing a Roth conversion.
Here's what TurboTax says about Roth Conversions.
https://ttlc.intuit.com/replies/3302189
