How do I make a LinearLayout scrollable?

Place your layout in a ScrollView.

<?xml version="1.0" encoding="utf-8"?>
<ScrollView ...>

    <LinearLayout ...>

        ...
        ...

    </LinearLayout>

</ScrollView>

<ScrollView xmlns:android="http://schemas.android.com/apk/res/android" 
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:gravity="center|left"
        android:orientation="vertical">

        Your views go here...

    </LinearLayout>

</ScrollView>