Yes, simply download and install. But make sure you return the license of 32 bit back before installing so that you can use that to activate your 64 bit license (in case you have stand alone license)
I had been running SW2009 fine on Win 7 and like me there are many people running SW2009 on Win 7 successfully, so I think there should be no issues at all. And even if you search on the forum, you will get many threads/posts on SW2009 with Win 7
I still see them on the SW download site so that would be the logical place to grab them if you don't have the original DVDs & service packs.
WT