Base64 decoding

[gimme_this_gimme_that]

I'm using Xalan on UNIX although I'm interested in any solution ...

Is there a way to transform this XML code having this
Base64 encoded element "PREREQUISITES" :

<ROOT>
<PREREQUISITES SQLType="BLOB"
encoding="base64binary">RmFtaWxpYXJpdHkgd2l0aCBhIFdpbmRvd3MgdXNlciBlbnZpcm9ubWVudDsgZmFtaWxpYXJpdHkgd2l0aCBPZmZpY2UgWFAgV29yZCAyMDAzOyBiYXNpYyBlbmQtdXNlciBleHBlcmllbmNlIG9mIHRoZSBJbnRlcm5ldCBvciBhbiBpbnRyYW5ldA==</PREREQUISITES>
</ROOT>

into text :

Familiarity with a Windows user environment; familiarity with Office XP
Word 2003; basic end-user experience of the Internet or an intranet

Thanks.