The bolt holding the blade on is stuck and I can’t undo it to get to the belt to replace it. Any tips on undo it?

Undo the bolts holding the alternator but do not remove them, move it so it loosens the belt, remove old belt, replace new one, move alternator to tension belt, then tighten bolts!

un do the bolts that hold the seat belt rewinder
take out the back seat and then undo the bolt that holds seat belt to floor of car then install whole replacement seat belt unit inset and retighten the bolts.
http://www.carparts.com/toyota/camry/seat-belt

Wrenches-- loosen bolts holding it in place, move it so belt comes loose. lift belt off pulley, undo bolts and remove alternator. use reverse process to install.

you half to take the belt off then the alternator then the bracket that holds it on undo the top rad hose then undo the the lines to the compressor and un plug the wire's undo the 4 bolts and pule it out

First, don't hold bar on cog as you will damage those and ruin it. Using the starter is a good way to damage starter or flywheel.

Soak the bolt with PB Blaster or WD40 and let is soak for a day. Use a large impact gun (3/4 or 1") with plenty of air flow and pressure.
If that does not work, then use a torch to heat the bolt head (not red hot or anything like that), then strike the bolt head straight on with a brass rod using a heavy hammer (32oz or so). This will break any corrosion that has welded the bolt head to the balancer.
Then use your wrenches again.
If that does not work, then try this: How to remove stuck harmonic balancer bolt

2002 frontier 4 cyl: 1) take off air intake tube, 2 screws 13 mm above radiator. 2) 1st belt for power stirring has pulley, undo pulley screw and unscrew adjuster bolt enough to take belt off 3) 2nd belt for alternator and water pump has no pulley but adjusting bolt and mounting bolt on alternator pulley, loosen mounting bolt and unscrew adjusting bolt enough to take belt off, if alternator will not move go under the truck and remove plastic cover- 6 screws 13 mm heads, after that look directly under alt. Pulley and should see a screw head 9/16 in, loosen it so alternator can move, now should be easy to remove belt ( it will be a lot harder to put new one though) 4) 3rd belt for compressor has pulley so follow #2 to remove it ,have to be done under the truck. First 2 belts will have to work around fan blades to remove them so wear gloves. After replacing belts remember that not to over tighten bolt on pulleys.

Replace window regulator and motor. Procedure: Remove inside door panel, cut regulator wires, raise window manually and hold in place, undo bolts holding window glass to regulator, undo bolts holding regulator to door-frame, remove regulator. Reverse to install.

the one on the engine ?? two bolts either side ,cant remember but yes you may have to remove the fan belt tensioner thinking about it ,quick tip ?? to undo the bottom crank pulley bolt ,use a knuckle bar on socket and jam the knuckle bar into suspension then crank with starter motor ,undoes them everytime it does.Then before you slacken anything to do with the timing ,bring it around to TDC no 1 and paint all the pulleys to the block with white paint ,except the water pump and idlers .

hold fan belt with both hands as if stretching a rubber band.place one end of belt over a fan blade all the way down to the hub.loop the other end over as many blades as length allows.''leap frog'' over remaining blades as necessary.if that doesn't do,there should be 4 bolts holding fan hub to it's mount on water pump spindle

to take fanclutch off undo the big bolt, fanclutch will come off