Yes the pulley bolt can work loose and allow the crank pulley to slide forward enough to allow the drive belt to hang up. Can be very damaging to stuff under the hood.
I just removed my crank pulley to get at the lower timing belt cover. The bolt is installed with about 190 foot pounds of torque. The engine in on a stand and we had to lock down the start ring and use a pull bar with extension to get it to break loose.
Once the shaft bolt is out, the pulley will need to be pulled. I use a puller with narrow enough slots to install pull bolts inside the wheel hub. WORD OF CAUTION Do not use an external clamp type pulley remover. The balance is set in rubber. If the hub is stuck, you can pull the external portion off the rubber and it will ruin the pulley.
I placed a socket against the crank for the center screw to rest. I was quite surprised at how easily my pulley slid off. I just hand screwed in the puller shaft and it came forward very easily.
Just REMEMBER that when you go back you will need to place the large torque on the bolt in order to get it tight enough to secure the pulley.
