Using FTP
If you have troubles while installing large components in your Joomla! (for example Phoca Gallery), try to install it with help of FTP:
1) Download component installation ZIP file
2) Unzip it on your PC
3) Copy unzipped files to tmp folder located in Joomla! root folder on your server (e.g. create a subfolder there: (Joomla! root) tmp/large-component/
4) Go to your Joomla! administration - Extensions - Extension Manager - Install from Directory (set the folder where you have copied the files - tmp/large-component/ ) - click on Install.
5) Now the component should be installed with creating menu items in administration (if your server has problems with memory, it does not need to lose time with uzipping the files on the server).
Using Phoca Commander
If you are using Joomla! 3 and you cannot use FTP, try to install Phoca Commander and try to install the extensions with help of Phoca Commander:
1) Download component installation ZIP file
2) Upload it in Phoca Commander
3) Unzip the installation ZIP file to tmp folder located in Joomla! root folder on your server (e.g. create a subfolder there: (Joomla! root) tmp/large-component/
4) Go to your Joomla! administration - Extensions - Extension Manager - Install from Directory (set the folder where you have copied the files - tmp/large-component/ ) - click on Install.
5) Now the component should be installed with creating menu items in administration.