GOOGLE IS YOUR FRIEND. 

How do I install a theme?

Go here → Click ‘Download’ → copy all of the code for the theme → ‘Customize’ your blog → click on the ‘Theme’ tab (make sure custom HTML is enabled) → delete the existing code there and paste the new code. 

If the colours are not right, click ‘Reset Defaults’ under the ‘Appearances’ tab and it should work out.

Why do the colours on the theme reset to their defaults if you change the html?

If you edit the colours or the other options in the Appearance tab they will automatically go back to what they were last saved as if you edit the html. It’s easier if you choose the colours you want, ‘save’ it, then edit the html so that you haven’t lost any of the changes.

How do you put an image in the sidebar?

Customize your blog → Appearances → scroll down and click ‘upload’ next to ‘sidebar image’ → choose your image → save changes. 

How do I add links to the top/sidebar?

Customize → Appearances → enter the link address next to ‘Link 1’ and the title next to ‘Link 1 Title’.

Is it okay to edit the theme as long as the credit remains intact?

Of course.

How do you remove the Source: ______ that lies under reblogged entries?

I don’t think that is possible, sorry.

How do I add a page?

Customize → Pages → Enter in the page URL you want, title etc. → Create page → Save page.

How do I make the description in my sidebar centred?

Customize → Info → add <center> to the start of your description and </center> to the end of it.

Why is my ask box not working?

You don’t have it enabled. To enable it go to your tumblelog page (e.g. tumblr.com/blog/insertblognamehere) → Settings → Make sure that ‘Let people ask questions’ is ticked → Save preferences.

THE FOLLOWING QUESTIONS RELATE ONLY TO THEME 1:

How do I keep the blog title visible permanently?

Find this: #blogtitle{margin-top:30px; margin-left:80px; font-family:century gothic; text-transform:uppercase; text-align:center; opacity:0; -webkit-transition-duration: 0.6s; -moz-transition-duration: 0.6s;} and change the opacity to 1.

How do I keep the tags visible permanently?

Find this: #tags{position:absolute; width:200px; margin-left:605px; opacity:0; margin-top:-23px; letter-spacing:1px; -webkit-transition-duration: 0.6s; -moz-transition-duration: 0.6s;} and change the opacity to 1.

How do I make my background fixed?

In the body{ section of the html, add this: background-repeat:no-repeat; background-position:right bottom; and you can change ‘right bottom’ to whichever position you want the background to be, left bottom etc.
You’ll also have to find this: #belowabove{background-color:{color:background}; background-image:url(‘{image:background}’); background-attachment:fixed; and delete the bolded part (make sure it is the #belowabove section).
Now it should work for you when you upload the background.

How do I completely change the theme so that it looks how I want it to?

Google it. Look through different sites which offer html or css help and learn how to do different things yourself. Sorry, I don’t have much time these days to help with different css problems.

Why is my theme not working? Why aren’t the colours right? Why can’t I upload a sidebar image? 

Use the OLD customize page! Not the new one! You can find it here: tumblr.com/customize-classic.

If your question is none of the above, ask here! Be warned, I’m only answering technical problems with the theme. This means that questions such as, How do I make the links rounded? How do I put the tags beneath the posts? etc. won’t be answered.