oil and coolant

sup guys.... just wanted your personal opinion... ive been running 5w30 synthetic since ive got the car brand new and been keepin up with my oil changes every 3k. now what i want to know is if its a good idea to switch to 10w30 synthetic... what are your guyz opinions?? should i stick with what im doin now... or is it best to change. and can anybody give me a quick runthrough as to how i can change my coolant... im runnin up on 30 k. so i think i have to change it... the plugs and wires im waitin till march to do... anyhelp would be awsome... thanx guyz peace...

im running 10w30 synthetic. no problem.

as for the coolant.

turn the AC temperatureknob to hot.
run the engine til the coolant warms up.
remove the radiator cap, radiator drain plug and engine drain plug.
watch out for the hot fluids. use a towel or something to protect u.
remove the reserve tank and drain the coolant.
reinstall the drain plugs and flush with a radiator cleaner
when you are done flushing, drain the fluishing fluid
put everything back together.
add coolant at the right ratio of water to coolant
reinstall radiator cap
start the car and let it warm up til the thermostat opens
rev the car to 3k rpm several times and then stop the engine
carefully remove the radiator cap and fill up the radiator again.
add radiator fluid to the reserve tank

disclaimer. it ain't my fault if u mess up