Need some help please.  My Brother picked up a 1993 XR 100 for free.  It had been crashed on its left side, broke the case cover and bent the shift arm.  It is in gear and will not shift into neutral or another gear.  I am pretty sure that with a bit of help we can fix this.  What I need is options of what this may be.  Is it a broken shift arm, bent shift dogs or possibly some thing else? To tear it apart and change out a shift arm or replace other possible problem parts will we need any special tools?  Yes I will pick up a Honda service manual for it and we do have all the normal bike/automotive hand tools.  I have worked on my own bikes (minor stuff) for the last 20 years but have not tore open the bottom half of an engine before.  Please email me at racerx303@hotmail.com.  Thanks for your help.