Change the oil on a Lexus RX 350 by removing the oil filter drain bolt, using a drain hose to drain the oil, removing the filter housing, installing a new filter and refilling with 6.5 quarts of fresh oil. This job requires a ratchet, several sockets and possibly an extension.
Remove the oil filter drain bolt using a special oil filter socket. Many mechanic's tool kits include these sockets, and virtually all auto parts stores also carry them. After removing the bolt, snap a plastic drain hose into the socket, and place a pan under the hose. Allow the oil to drain fully from the filter housing before removing it.
Remove the oil pan nut and the old crush washer. The crush washer is one-time use part; replacements are available from any certified Toyota or Lexus dealer. Use a large socket to remove the entire oil filter housing; depending on your reach and ground clearance, this step may require a socket extension. Unscrew and discard the old oil filter and o-ring before installing the replacement. Coat the new oil filter's o-ring with fresh oil for a good seal before installation. Make sure the new filter is snug in the housing, but do not over-tighten.
After reassembling the entire oil filter and pan system, open the vehicle's hood and pour in about 6.5 quarts of fresh oil. Check for any leaks before starting the engine, then again after running it for a few minutes.