Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Norelco Battery Replacement

Removing the old battery was the challenge. I didn't want to risk unsoldering the old battery from the circuit board because I thought the risk of buggering the circuit board too great. Instead I used a Dremel tool to cut off the old battery leads at the battery connections. This entailed very carefully cutting the top off of the old batteries and then trimming. It was not a trivial task but not impossible. Then I gently blew the inside of the shaver out with compressed air to remove any metal shavings and other debris. Once this was complete it was easy to solder the new battery leads to the old batter leads, reassemble the shaver and charge the battery the conventional way. It works great.