If downloading transactions, these will come through as a Buy and a Sell. But it is really just a rename. So if you have that situation, say so. There are special steps to get the future downloads to match the renamed security.
Another way, appropriate to a tax-free buyout, is to do Portfolio->RecordASpecialActivity->RecordAMerger
This keeps data and reports separate. Money enters a Buy and Sell, but transfers the basis to the new survivor. There are hidden things associated with the Sell and Buy. You will have separate histories. This is the way Money was designed. It may be easier for downloads than the rename method.
If these don't seem to address your situation, please elaborate on your situation.