Please refer to the following steps to update/upgrade your server resources.
1. Log into your ControlCentre (http://www.bytehouse.co.uk/controlcentre)
2. In the 'Subscription' drop-down menu, select the relevant server
3. Click 'Buy Resources'
Select the resource type that you need, say, 'SLM memory limit' is the RAM resource.
In case you have already reached the maximum possible upgrade limit for a particular resource, you will have to upgrade the hosting plan.