there are two schools of thought on this.
Some say that if you keep on handling the monitor, it will eventually get tame.
Others feel that this will make the monitor wilder, so instead opt for the calm approach of doing what you'd normally do (spot clean the enclosure, change water dishes etc) but leave the monitor alone and let it get used to you being around, then slowly trying to interact with it in its enclosure without lifting it up. Eventually it may allow you to pick it up and may even crawl onto your outstretched palm on its own. This is my preferred method.
Whichever you chose, don't ever remove it from its hide spot. The monitor needs to feel that it has at least one spot that is completely safe from your prying hands.