Do you know what do you mean by reciprocal link. Difference between reciprocal link and regular link is that both provide back links but for reciprocal link building you have to put their site link on yours. Reciprocal link is mutual link between two website.
First of all you have to design one page for reciprocal links, or you may add links on existed page. Its on you. Just copy their html tag on your site
Suppose this is your site "http://seo-doctors.blogspot.com"
Just make change in your code and put their given code on your site. like <a href="http://seo-doctors.blogspot.com">SEO Doctors</a>
And after this put your URL "http://seo-doctors.blogspot.com" in the box of "Reciprocal Link URL".
This is simple way to make reciprocal link for you. All the Best!