Disconnect your battery negative cable before removing the motor / rack!
The skuds wipers were incredibly slow, fast speed remained the same.
I removed the wipers motor and rack
Removed the circlips at the wiper arm ends of the wiper cranks
remove the washer and the O ring below and keep spraying penetrating fluid from both sides of the shaft (there's no O ring at the base end of the crank shaft, just a washer). Pop the ball joint off the base of the crank
Clamp the base of the crank in a vice (I had to smack the tommy bar of the vice with a hammer!) and continuously rotate the rack to help free the shaft whilst pushing the housing off the shaft. The passenger side took 10 mins of winding backwards and forward to get it out, the drivers side took 30 mins
, lube continuously!
Once the cranks are out emery cloth the shafts to remove the corrosion, the cranks shaft housings have a pressed bush at each end, between is powder like corrosion and old dry grease that causes the shafts to seize, scrape out the crud and wash out with wd40.
Clean, dry, silicon grease (silicon to protect the seal from perishing - thanks wild Bill) and reassemble.
Don't be tempted to hit the shafts out, you'll damage the thread!
Mind those fingers, these are basically a guilotine and will cut your fingers off!
Clean out the scuttle drains to prevent water ingress into the foot wells.
Refit the wiper motor / rack, plug the wiring back in, reconnect the battery, ignition on and the wipers should self park (its highly likely the motor will move whilst removing the cranks), turn on the wipers and check both speeds and intermittent wipe functions, turn off the wipers and allow to self park (remove the ignition key) before refitting the wiper arms (a dirty screen helps to position the wipers in the same position as previous)
This would also be a good time to replace the pollen filter beneath the windscreen scuttle panel.
Regards
The skuds wipers were incredibly slow, fast speed remained the same.
I removed the wipers motor and rack

Removed the circlips at the wiper arm ends of the wiper cranks
remove the washer and the O ring below and keep spraying penetrating fluid from both sides of the shaft (there's no O ring at the base end of the crank shaft, just a washer). Pop the ball joint off the base of the crank
Clamp the base of the crank in a vice (I had to smack the tommy bar of the vice with a hammer!) and continuously rotate the rack to help free the shaft whilst pushing the housing off the shaft. The passenger side took 10 mins of winding backwards and forward to get it out, the drivers side took 30 mins

Once the cranks are out emery cloth the shafts to remove the corrosion, the cranks shaft housings have a pressed bush at each end, between is powder like corrosion and old dry grease that causes the shafts to seize, scrape out the crud and wash out with wd40.
Clean, dry, silicon grease (silicon to protect the seal from perishing - thanks wild Bill) and reassemble.

Don't be tempted to hit the shafts out, you'll damage the thread!
Mind those fingers, these are basically a guilotine and will cut your fingers off!
Clean out the scuttle drains to prevent water ingress into the foot wells.

Refit the wiper motor / rack, plug the wiring back in, reconnect the battery, ignition on and the wipers should self park (its highly likely the motor will move whilst removing the cranks), turn on the wipers and check both speeds and intermittent wipe functions, turn off the wipers and allow to self park (remove the ignition key) before refitting the wiper arms (a dirty screen helps to position the wipers in the same position as previous)
This would also be a good time to replace the pollen filter beneath the windscreen scuttle panel.
Regards