How to remove hob in order to replace hotplates?

I have a Leisure Rangemaster 110 Electric Green cooker Year 2000. I wish to replace all 4 hotplates.
1. How do I remove the hob from cooker?
2. Back left plate is a simmerstat type. Can I replace it with a standard solid type & will this require any changes to the wiring or the regulator.
3. what are the correct specifications for these hotplates. The large is 2000w & the small is 1500w and where can I get these replacements