There is no exact code change to be made for those settings.
to increase the upload file size to 6MB, you need to increase the
upload_max_filesize
post_max_size
The post_max_size setting should be larger than the upload_max_filesize
to increase the script execution time, you need to adjust:
max_input_time
max_execution_time
if there image resizing occurring, you will also need to adjust:
memory_limit
if you are resizing images, you should increase the memory_limit to 256M