When the price hits the top of the channel, sell your existing long position and/or take a short position. When the price is in the middle of the channel, do nothing if you have no trades, or hold your current trades. When the price hits the bottom of the channel, cover your existing short position and/or take a long position.
If the price breaks through the top or bottom of the channel, then the channel is no longer intact. Do not initiate any more trades until a new channel develops. If the price drifts between the channels for a prolonged period of time, a new narrower channel may be established. At this point, enter or exit near the extremes of the narrower channel.