Sterilising swing top bottles for Cherry Brandy

My two large 'le parfait' jars of cherries steeped in brandy have been there since last July and now i need to decant them into my Grolsch swing top bottles. What's the favoured method for sterilising the bottles? I was going to dry bake them in the oven? If so, how long would be sufficient. I give my jam ones 5 minutes at 150°c and the jam is still fine a year later.....

Thank you for that although, like my jars, i'd have removed the rubber seal of the porcelain stopper!