If Toshiba really want to sell the memory business...
The problem with them selling it is the JV agreement with Sandisk.
From other reports, it seems that there is a clause in the JV that says something along the lines of needing permission from the JV partner to sell off any interest in the JV, and WDC (via it's Sandisk subsidiary) is refusing that permission.
Now, Sandisk got around needing Tosh's permission because Sandisk hasn't sold/transferred any if its share of the JV assets to WDC, it sold the entire company, Sandisk, to WDC, not the JV assets. Sandisk still owns and is the partner in the JV, it just so happens that now WDC owns Sandisk outright. So whenever writers or people say "WDC isn't allowing...", what they mean, technically and legally, is that Sandisk isn't allowing it. It just so happens that WDC can order Sandisk what to tell Tosh.
Based on the above, then the following, or some variation of, may work if Tosh really want to sell it's share of the JV:
It could create a new company, say ToshibaSan, and transfer (via whatever legal means companies spin off subsidiaries etc.) all the non-JV assets/liabilities, all the ones it needs to keep, to the new ToshibaSan. Then it could change the names of the companies, rename Toshiba to FUWDC, and then rename ToshibaSan to Toshiba (so it can keep the name if it wants to). Then it could sell the 'old' Toshiba, now called FUWDC, that now only consists of the JV elements, to whoever wants to buy that company, in its entirety, selling the company that happens to contain the JV assets.