buy a bearings & seal kit - under £25 easily
liberal amount of sealant on drum seal when fiting
check the spider isn't skuffed - if you earlier as you described you'll be ok there
take photos of everything before you touch or remove - can take time but 10% of the time if you get it wrong
slowly but surely is where my successes are
if you a sparky then i not in your league - mornings work for you i'd guess
one thing i found very helpful
cling film new seal & bearings individually & tightly
freeze for 24 hours
then when you fit them on heat the spider , drive them on with the old bearings as the shield and they'll tap on easy
good luck