You can't with NaOH. But you could do some selective protection chemistry. Hm... this is a little tough. You could probably get decent selectivity protecting just the primary alcohol with 1 equivalent TMS. Isolate, then protect the tertiary one with TBDMS. Water or a little weak acid will only deprotect the TMS. Then expose it to base. TBDMS ethers are reasonably base stable as long as its not highly concentrated/hot NaOH. Boom.