To properly paraphrase, you must change 2 things from the original source:
You must also still include the author(s), page number(s) (for MLA), and date (for APA).
Let's look at a couple of examples:
Our first sample text is from the article "Impacts of Regulatory Reform on Intercity Bus Service in the United States," by Clinton V. Oster, Jr. and C. Kurt Zorn, which was published in volume 25, issue 3, of the journal Transportation Journal, in 1986.
Prior to the mid-1970s, the major modes of intercity transportation, with the exception of the automobile, were subject to federal economic regulation.
Correct paraphrasing (MLA):
According to Oster and Zorn, the federal government regulated the economic aspects of most means of transportation between cities (except for the automobile) before the mid-1970s (33).
Here is another way you could paraphrase this sentence - this time, we will cite is APA:
According to Oster and Zorn (1986), the federal government regulated the economic aspects of most means of transportation between cities (except for the automobile) before the mid-1970s.
The second sample text is from the article "That Guy's A Batterer!: A Scarlet Letter Approach To Domestic Violence In The Information Age," by Elaine M. Chiu, published in volume 44, issue 2 of the journal Family Law Quarterly, in 2010.
Despite the remarkable reliance of the Internet as a source of information, we have yet to fully take advantage of it in our movement against domestic violence. The movement has been around for a long time now, and it has had an enormous impact on the ways we view domestic violence. Nevertheless, domestic violence continues to occur at worrisome levels and to be a serious problem for our communities. As a result, the movement against domestic violence has reached a stage where its members are hotly debating the success of the changes they have implemented. There is significant disagreement and conflict over whether reforms over the past thirty-five years are working or whether the movement needs to find new approaches.
Correct paraphrasing (MLA):
The movement against domestic violence is at a critical juncture. Some members of the movement think that the reform of the past thirty-five years are effective; however, despite the strong impact of the movement on social perceptions of domestic violence, domestic violence is still a major problem. Other activists believe the movement should explore new approaches. The internet is one potentially useful tool that the movement has not yet used to its full potential (Chiu 255).
Here is another way you could paraphrase this passage - this time, we will cite is APA:
Chiu (2010) points out that while the movement against domestic violence has undeniably experienced much success during the past thirty-five years, domestic violence is still endemic in society. The mixed success of the movement has created much debate among members regarding whether the reforms of the past few decades are effective, or whether the movement needs to explore new approaches. Chiu suggests that activists should take great advantage of the internet as an information tool (255).