Decoding data from Base64 string

Hello, I am new to SoapUI. I am running a test script in SoapUI that has x number of steps. Each step returns a base64-encoded PDF in the response. Currently, we take the base64-encoded data and decode it using the following tool: http://www.motobit.com/util/base64-decoder-encoder.asp

I need to be able to automate this step.

Any suggestions/recommendations would be greatly appreciated.

Thank you.