Why do you think the valves need adjustment?
Did you chase down the noise from the serp belt system?
FWIW, push rod type engines have a tendency to tick, even when the valves are in proper clearance specification.
I adjust the valve clearance on my '81 Honda CS500C every pre-season tune up. It is a push rod type engine. It sounds like a sewing machine at idle, it has a soft but audible tick.
I would suggest this is beyond the average DIY mechanic. Engine position is critical for each cylinder on both intake and exhaust valve clearance. I can't say for the 4 cyl, but I've read the procedure for the 1GR-FE. The procedure is not difficult, but it needs to be precise and followed exactly. So, go to a Toyota mechanic and have them assess the need and/or do the work.