The answer to 'how to unclog pipe repair' is to use a plunger or a drain snake to clear the clogged pipe. Start by trying a plunger, which can often dislodge a simple clog. If that doesn't work, use a drain snake or auger to physically break up and remove the clog. Be sure to wear gloves and eye protection, and work slowly and carefully to avoid damaging the pipes.
If the clog is severe or you're unable to clear it, it's best to call a professional plumber. They have the right tools and experience to safely and effectively unclog your pipes without causing further damage.