A:AnswerThe short answer to your question is you can't.
Although these are allegedly IP65 waterproof rated, the controller near the front of the strand (effectively the "brains" of the system) is not. Unfortunately, this design flaw kind of defeats the purpose of outdoor use without some sort of after market protection added to this vulnerable area.
Additionally, there are lots of complaints online about the bulbs collecting water. Another poor choice on the engineering of the strand was to have each wire connection point at the top of each bulb (rather than the sides), which basically guarantees that water will leak into the bulbs over time.
For the price and features, the product is adequate. However, I would not recommend using it in an area that may be exposed to moisture for any more than a few minutes.
A:AnswerI've had mine for a couple of years now. I had the same thing happen on the last bulb in my set, and started flashing white. I requested a refund and was given a refund, and asked about returning them. I was told to keep them. The problem went away. I observed I could unscrew the bulb cover, so I removed it and allowed it to air out, and put the bulb cover back on, but tighter. It has happened one other time since then, but also went away. Overall, I have been very happy with the lights.