check the step by step guide for configuring multiple SSID in autonomous APhttp://www.cisco.com/c/en/us/td/docs/wireless/access_point/12-3_7_JA/configuration/guide/i1237sc/s37ssid.html

Its due to DHCP lease as the client already have the old address its better that you make a new scope and so that the new client gets the ip after the default lease expire then you can switch to the original lease. ***************Do rate helpful post...

yes 4500-X can be a better and optimal choice as you are moving from old 6500s .Data sheet for 4500-x Vs 6500Ehttp://www.cisco.com/c/en/us/products/collateral/switches/catalyst-4500-x-series-switches/data_sheet_c78-696791.htmlhttp://www.cisco.com/c/e...

check Cisco how to guides for step by step configuration just follow the instruction and you can easily  configure the setup also when you first open the ISE there is an option for express setup (Auto config) but i would suggest for the guide (link g...