Moving to Themes forum...
If you want to add a new image you first need to deleted the slider images and then add new ones in the same way you added to first one. All image settings in themes allow you to do this, so I am not sure what you are finding difficult.
Perhaps you did not find the Roshnilite settings page? Try looking in...
Administration > Site Administration > Appearance > Themes > Roshnilite
Also, since you are a person new to Moodle, then I feel it is my duty to have to warn you that:
Before attempting to change anything in Moodle:
- ENABLE Debugging: Choose DEVELOPER setting.
Administration > Site Administration > Development > Debugging
- NEVER change Moodle code unless you know what you are doing.
- READ all the Moodle docs on the subject in an attempt to learn something about that which you are attempting to change. Also make sure you read the Moodle doc written for the version of Moodle you are using.
- if you are using a contributed theme, and need assistance then please ask in the Comments section of the theme you downloaded from the plugins repository.
Since you have pointed out on no change should be made in the original codes. Can you tell me what all I should do and take care of while working with Moodle code if I wish to work for an organisation who are looking up to implement Moodle for some other organisation??
I found out how to change the images. I need to know where to find the style sheet for this theme's front page as i do not want this much height for the slider. i want to reduce it a bit. I think you did not see the screenshots. i have mentioned that i could see the code on browser but couldnt find it in th emoodle folder. any help on that??
and about the changes, I believe we can make as much changes as we want in themes to make it according to our creativity.
for example i found reference to this site https://learn.unitedforwildlife.org on moodle community. i believe this is aversion of the roshni lite theme. Please correct me if i am wrong..
Of course you can do whatever you want to a theme, providing you know what you are doing, but as a first timer to Moodler I thought you are better knowing that you need to find out about the theme first before you start to mess with it. You obviously do not know much about Modle themes, although you may be a wiz-kid on a computer.
All the CSS files are found in the roshnilite/style directory. These files will be listed in the roshnilite/config.php. So that's the place to start. It is actually easier if you have your theme files on your desktop so that you can look through them, rather than on the website. Knowing what you are looking for is half the battle. In other words get familiar with the theme files. If you need to change them then you can do that via the file manager on your website.
From memory when I saw the theme creators presenting about that unitedforwildlife theme, no it is nothing to do with Roshnilite at all. It was created by them inhouse and with several other developments to course formats etc that they used for the site. Its not an adapted roshnilite theme.