Glass cracked from age, over 27 years

Remove modular element from cooktop,place upright on bench and remove sheet metal screws. Lift glass/rim subassembly from modular heating unit (screwdriver may be required to carefully pry glass/rim assembly from heating unit) as it may be a tight fit. Inspect exposed heating unit for any noticeable damage, clean any debris resulting from cooking spills, etc. Use caution in cleaning area around heating elements so as to not damage insulation. Install new glass/rim assembly using original screws. Do not overtighten screws as this may distort the sheet metal assemblies. Install in cooktop and test for proper function.