Hi, last week a car wash decided to destroy my rear windscreen wiper arm. I've sourced a new one but I can't seem to get the old one off. It's a mk3 octavia Estate 2017. I've removed the bolt and given it some wiggles also applied wd40 but it won't budge. Am I missing something? Don't want to break it even more forcing it. 

First thing is WD40 is useless - it's a Water Dispersant, not a penetrating fluid - so best to use Plus Gas or some other proper release agent. 

 

It's probably corroded on, so might be useful to apply heat to the remnants of the arm, hot air gun etc., but be careful to protect the screen.

Something similar to a bearing puller is ideal, applying pressure to the arm and using the central mount as a lever to pull it out. Its held on by a combo of friction and the bolt so it's likely that penetrating fluid will loosen it up alone

Just seen you can get a puller for around six or seven quid on Ebay, much cheaper than a replacement rear screen 🤣

Thanks I've got one coming from amazon today so hopefully that will work 👍