My Spectrum Modern 4-4-0 came with a set of replacement domes.  How do I switch them out?  Do I have to take the whole unit apart to
reach the inside of the boiler?

Does the 0-6-0 tank locomotive have a bulb headlight or the older optical type"
 Thanks

I have five Bachmann Spectrum locomotives.  Only two run adequately.  The other three all start and stop frequently.  My track is clean and I have cleaned the wheels.  Other locos run fine but these three are always a problem, a Baldwin Modern 4-4-0, a 4-6-0, and a Shay.   It apparently is an electrical pickup problem.  If I disconnect the tender and the the pins from the locomotive the sound in the tender will work, until you touch the tender or move it.  Sometimes it will start again on its own.  Sometimes you have to jiggle the tender to get the sound working again.   I'm not sure how to solve it.  Any ideas?  Very frustrated and fed up with Bachmann.