In this case, you'd only need to keep your seed safe, as was said, you just close your channels (force close.)

I'd chat to some people first to check whether or not you can resync your node to the channel-graph.

If you do need to force close channels use mempool.space to check the mempool, and forceclose when the mempool is clear (like weekends) this will minimise any fees incurred when closing/opening channels.