IBM T42 take apart, disassembly, disassemble, how-to video (nothing left) HD - YouTube
IBM ThinkPad T42 Repair - iFixit
Laptop,IBM ThinkPad T42, Pentium (R) M Processor. @1.70GHz ,512 MB RAM, No HDD, DVD-ROM , Windows XP Professional Licence Sticker, No Charger, Appears To Function [92882+22]
RTC BIOS CMOS Battery for IBM Thinkpad T40 T41 T42 T43 T41p T42p T43p 02K6572 | eBay