While an adjustable wrench can sometimes work, a basin wrench (like the Husky or TEKTON models mentioned) is highly recommended. It's specifically designed to reach and loosen/tighten mounting nuts in the tight, awkward spaces under your sink, making the job significantly easier and less frustrating for beginners.

If the under-sink valves are stuck or faulty, you'll need to locate and turn off the main water supply to your entire house before proceeding. If you're uncomfortable doing this or if the main valve is also problematic, it's best to call a professional plumber to avoid potential water damage.

To prevent leaks, make sure all threaded connections are hand-tightened first, then snugged with a wrench, avoiding overtightening which can crack parts. Always use plumber's tape (Teflon tape) on threaded supply line connections and plumber's putty or the provided gasket for the drain assembly to create a watertight seal.

It is strongly recommended to replace old water supply lines with new ones when installing a new faucet. Old lines can degrade, become brittle, or leak after being disturbed, even if they look fine. Many new faucets come with fresh supply lines, or they are inexpensive to purchase separately.